My first amp was an April '65 Fender Bandmaster. A good month for these babies. It wasn't beastly loud like the Bassmans, but it was a super sweet, thick bold tone with a tremolo verging on frequency modulation. I swear my notes were ever so slightly 'bendy'. I know electronics and know there would be no rhyme or reason for this, but it was there with my blood red KAPA Continental electric. The amp I got in 1981 in 10th grade from my friend who scored it at a flea market for $25! It was fully working, and well broken in, as it was cigarette burned from left to right from forgotten cigs hanging over the front , and back, edges, but mostly front. Today it would be desirable for posterities sake to see all those burns, some 3/4's of the cigarette burned into the Tolex, some through to the wood. The caps were all good, no hum. It was a great amp I used for a long time. It being my first real amp it set the standard for what I would expect from any great amp. Personality! I got to know how that amp wanted to sound. It came easy because some working musician used that amp for years and found that sweet spot already. I see all of these people that still have everything they ever owned and loved. Oh' how I wish! lol I highly recommend the end of the CBS Fenders. I had an April '65 Princeton combo someone had cut into a head. Except it was a little tall, I liked the visible top of the speaker cutout when looking into the back.

@theguitaramptech

4 ай бұрын

What a wonderful recollection, Paul. Thank you for sharing this important part of your life.

@paulj0557tonehead

4 ай бұрын

@@theguitaramptech You are very welcome. Thank you!🙂

I bought an old truck in the 90s and found later that the previous owner had used a 22lr (long rifle) shell in the fuse box to fuse the head lights... I called him to ask what that was about and he explained that he was fishing at night, and the was using the truck lights for lighting, and the fuse popped. Apparently the rifle shell was all he had at the time and neglected to ever change it. lol... Im glad I found it before it became a major issue...

@theguitaramptech

4 ай бұрын

OMG! That takes the cake. Did you ask him what the current rating of the shell was? Lucky he didn't use a live round. 😂

Great vid and enjoyable delivery!

@theguitaramptech

2 жыл бұрын

Gee, thank you Nick. That's very kind of you.

I did some servicing work on a mid-70's (at least that's what I think it is) Fender Super Twin non-reverb amp, that a mate of mine sold to me for only $300.00, it uses a total of six 6L6 power valves to produce 180W RMS/395W Peak (Yikes!!!!!!) of very clean power output, it just needed some minor things sorted out and a new 3-pin mains plug and lead fitted, I found out that my soldering station wasn't quite up to the job of de-soldering the old earth wire from the chassis, so I had to pop into my local Bunnings shop to but a new 50/100W soldering iron which did the job, the amp is working great now, I use it as a Bass amp.

@theguitaramptech

Жыл бұрын

That was a crazy loud amp. A huge clean sound, but we have no use for them in todays music scene. I use a 120w Weller for my chassis work. 80w minimum.

This is highly addictive stuff.

@theguitaramptech

3 жыл бұрын

Thanks Rob

The silver tolerance bands on those dropper resistors on the power supply filter cap board indicate that those resistors have a +/- tolerance of 10% of the marked value.

I'm currently restoring a '66 Bandmaster and this video has been a massive help. Thank you so much!

@theguitaramptech

3 жыл бұрын

It makes me happy to know that I could be of help, Mac. What a great amp you’re working on. Enjoy the journey. Chris

Way to go Sherlock!

@theguitaramptech

4 жыл бұрын

Thank you Dr Watson...I mean Dr Fenandez

Always interesting seeing you go through these vintage amps Chris, step by step...Sounded great and I like the song you played at the end... Phil NYC Area

What a great resource to have online! My '65 Bandmaster is acting up and this video will really help me sus out what needs to be done. I'm an experienced guitar tech but I've only done a couple tube swaps/biases and they were on modern amps. Hopefully I can nip the issue in the bud but at least I'll have a better idea of what to say when I bring it in somewhere. Thanks so much!

@theguitaramptech

3 жыл бұрын

Crispin Cotton-Kinch My absolute pleasure. I’m happy I was of some help.

Cool old amp. My first real guitar amp was a blackface Bandmaster. On my old Super Reverb, I connected the redundant ground switch to the negative feedback. With NF turned off the amp transforms from a refined sophisticate into a brick-throwing hooligan. It's a nice feature to have on a switch.

@theguitaramptech

4 жыл бұрын

HAHAHAHA! I love it! A "brick throwing hooligan". Hysterical! That's a great idea about the NF switch. Can I please borrow that? A blackface Bandmaster as your first amp?? Can you hug your parents from me? My first amp was a solid state Aussie "Savage" amp. I still love that cool 70's look. It still doesn't work, and its not good enough to spend any time repairing, but I can't part with it. You can see it on top of my book shelf in a couple of my earlier videos.

@Splattle101

4 жыл бұрын

@@theguitaramptech The old Bandmaster story isn't that cool. I started guitar late, and bought it when I was 19. I needed it urgently to go play in a band. It was cheapest 30-50 W amp I could find: everybody wanted Marshall back then.

I started playing guitar casually in 1959. Bit more in 1960 and whole hog in 1961. So I've seen a lot of Fender amps as new amps. The Bandmaster brownface and blackface and even silverface versions are under appreciated in my view. I was just 17 in 1965, but even by then I knew there was something different to them in the electronics because the BF's had such a nice, tight bottom end which was great for rhythm guitar. I later found I was correct when I learned about the rectifier system they had.

@theguitaramptech

Жыл бұрын

What a great time to be playing guitar, Tonetwister. You would have seen the world's best creating history. I Hope you got to see some of them. I agree with you 100%. about the Bandmasters of that era.

@Tonetwisters

3 ай бұрын

Good on you for having those understandings! First "big" group I saw was The Kingsmen of "Louie Louie" fame. Got to meet Sonny and Cher at the Jacksonville Veterans Coliseum; saw The Four Seasons on a bill with Roy Orbison and The Candymen (a friend would later join the Candymen as drummer and tour England with The Beatles (Robert Nix). Saw many other groups: The Rascals, a garage band called, Little River Band ... The Dave Clark Five, Jethro Tull, The Allman Brothers on the same bill as Frank Zappa and the Mothers of Invention! (WITH FLO AND EDDIE!!) My brother played rhythm guitar in the early '60s with a group called, The Classics that went on to be The Classics IV of "Spooky" fame. I live in Jacksonville, Florida, home of bands like Lynyrd Skynyrd and Molly Hatchet and .38 Special and The Allman Brothers (and now, Tedeschi Trucks band -- I drive by their house all the time). I used to play a downtown Jacksonville club called, The Comic Book Club during the same era the One Percent and The Allman Joys were playing down there. I wanted to see The Searchers 24 July 1965, but our band had to play a little town called, Palatka that night. Lost my 1954 Stratocaster (serial no. 0517) out the back window of my brother's station wagon on the Jacksonville expressway, early morning of 25 July1965. I always felt that I was born in THE GREATEST PERIOD OF HISTORY for music ... my parents played BIg Band from WWII, I was there for the very start of rock 'n' roll, got to hear "409" by The Beach Boys when it first hit the charts, got to hear Doo Wop, Soul, Chuck Berry, Buddy Holly, Elvis, The Platters and on and on, when they were first played on the radio. And I was already in a band when The Beatles broke. How's all that for some history? And my brother had a music store in Tallahassee, Florida where I got to tell John McVie -- face-to-face -- that I was out of Rotosound Bass strings! And my brother had a 16-track MCI analog recording studio where I got to learn engineering and produced some songs over three years. I played out weekends for probably 42 years. Hauled around a '64 Super Reverb I bought brand new (still have it!) and a Twin Reverb and a Farfisa Combo Compact Organ for years. Whew! I'm tired just typing all that!@@theguitaramptech Two songs I produced, by David Griggs: kzread.info/dash/bejne/enaVxJmIj9rQl84.html kzread.info/dash/bejne/a5eFudSRqMWnlto.html Thanks for commenting! Sorry for being so garrulous, here! God's blessings upon you! And oh yeh ... I just bought a nice 1967 Bandmaster to go with my 1962 Bandmaster!! 🙂

As a former Fender and Peavey warranty tech myself, I am pleased to see the care and experience you bring to the table. Great work and Happy New Year to you.

@theguitaramptech

3 жыл бұрын

Wow! That is so nice of you, MT. That means a lot coming from you. All the Best for 2021

This is cool! I'm in Nova Scotia, Canada, and my band master has transformers dated 27, 44, and 46th week.

@theguitaramptech

3 жыл бұрын

Very cool. Have fun setting up your amp. It’s a beauty.

Wow, great service and attention to detail..Also nice guitar riffs. Just learning all this stuff, and checking a few amp techs on You Tube. Awesome job, and thanks for sharing your knowledge..Ed..U.K..😊

@theguitaramptech

3 жыл бұрын

Thank you Ed. I very much appreciate your kind words. In addition to watching me, Uncle Doug and D-Lab, also try the Guitologist. I still believe in investing in yourself. Buy a book that’s right for your level and study it. Take notes as if you were in class. I did my university degree in electronics, but I still buy (expensive) books and give myself time to study. As my dad used to say “the more I know, the more I know that I don’t know”. Good luck

@edwardhannigan6324

3 жыл бұрын

@@theguitaramptech Thank you for your reply. I'll do that..Thanks for the tip..😀

Lovely sounding amp . Great work Chris.

@theguitaramptech

4 жыл бұрын

Thanks Andy. It is such a privilege to work on important old Fenders like this.

Well done on the mains work!

@theguitaramptech

4 жыл бұрын

Thank you, Mike

I saw that totally cooked screen grid resistor, yeah I'd replace it in a second too if I was working on that amp, definitely looks like it has been well and truly cooked till it's charcoaled.

@theguitaramptech

Жыл бұрын

Ouch! I forgot all about that, Simon. Charcoal is right!

I am glad I found your channel. I have been anrf tech all my life and just really got interested in audio circuits. I am retird now and look for interesting videos. I like the pride you take in your work. Greetings from the US.

@theguitaramptech

2 жыл бұрын

Thanks Monty ! I have done so many shows in the USA, I feel that it is my second home. I love the huge variety in landscapes and food. The people are super friendly (except for the universal "big city syndrome", including Sydney). I have made lifelong friends on both coasts and I can't wait for Corona to piss off so I can go back "home".

Just found your channel and I really love it. I am in the process of trying to learn/understand all of this stuff and I appreciate the time and effort you take to make these videos. I want to learn about this stuff because I am currently profoundly deaf after surgery to repair my one and only working ear failed earlier in the year. This is going to be a great hobby for me to start and will keep me occupied until after I have my Cochlear Implant fitted next year. I really want to be able to service and repair my own amplifiers. Thank you once again for the videos. Take care and stay safe👍🏻

@theguitaramptech

3 жыл бұрын

That is so kind of you Robin. Good luck with your operation next year. There is so much you can learn in the meantime. The Internet is a wonderful resource but I still invest in texts which challenge me and broad my knowledge. I would strongly recommend doing an electronics course after your procedure. The course can be on transistors or MOSFETs, if you can’t find anything on valves. They all operate in fundamentally the same way. Please go through Uncle Doug’s Channel. He was a teacher, and it shows. Good luck.

I see that you went with F&T caps as replacements for the old power supply filter caps, F&Ts are supposed to be really good quality caps but expensive, but I think the use of F&Ts as replacements in this amp is justified, since the owner is most likely to be gigging with it.

@theguitaramptech

Жыл бұрын

You're spot-on Simon. I haven't met many customers that have said "yes, I'll have the cheap shit option". I have also been trying the MOD brand of caps recently. They seem great, and cost less than the F&T, but I still go with he tried and proven F&T's most of the time.

"I am a brain, Watson. The rest of me is a mere appendix."

@theguitaramptech

4 жыл бұрын

Ah, my dear sir, I see that you comprehend that Mediocrity knows nothing higher than itself; but talent instantly recognizes genius...and I recognize it in you.

It's higher ripple when you draw more current

@theguitaramptech

3 жыл бұрын

You're spot-on Ian

hi, very informative , thank you.When you pulled the negative voltage to see if the coupling caps were leaking , as i understand, the output tubes were removed and the speaker load was plugged.The output transformer was still getting b+ from the red wire,if i'm right. Is it bad for it ?

@theguitaramptech

3 жыл бұрын

With no tubes installed, there is no path to ground for the OT primary to ground. Both plate connections (pin 3 on the socket) will have the full B+, but there will be zero current. (There may be a slight pulse of inrush current as the Standby is turned on, but will fall to zero). You are correct in saying that it would be very unwise to disconnect the negative supply with tubes installed.

The GT 6L6-S means Slovakian made, so JJ.

@theguitaramptech

2 жыл бұрын

Thanks Zack!

Evil guitar amp tech origin story.

@theguitaramptech

11 ай бұрын

HAHA! The game's afoot, my friend.

Why do they not mount the resistors a short distance away from the tube sockets? Heat always gets them.

@theguitaramptech

3 жыл бұрын

Thank you for that excellent question. One of the main function of those resistors is to act as a high frequency low-pass filter in conjunction with the input capacitance and the Miller capacitance to prevent high frequency parasitic oscillation. The best position for this effect is place the resistors directly to the pins . However, your comment is a very valid one. For this reason, I “hang” my resistors off to the side of the tube socket instead of in the direct line of the rising heat from the tube below.

@dougtaylor7724

3 жыл бұрын

I’ve seen equipment from 30’s to 50’s hang them on the side. Was curious if putting it directly on top was a production or interference thing. Thank for the info!

I like the info But I wish you put the camera in a better position and had your hand out of the way Thanks

@theguitaramptech

3 жыл бұрын

Thank you bob. I really appreciate your advice. In my next video, I will be using 2 cameras to overcome the problems of fat head and big hands. More editing, but if you’re patient enough to watch out for it (Princeton Reverb) I would really appreciate your comments.

I come give you a hand for more videos

Would it be safer to wire mains to the switch and then to the fuse to prevent shock if someone were to change the fuse with the amp on? I know when I was a traveling guitarist I have had been shocked by the old amp with hot fuse holders. Just wondering.

@theguitaramptech

2 жыл бұрын

Thank you Monty. This is a VERY IMPORTANT question. I understand that there are differing opinions, but the fuse should be the first thing mains power sees in our equipment. When a fault causes the fuse to blow, the power is isolated to the entire circuit and protects everything that follows including the switch, which has its own current rating limits. There is a very small, but deadly chance, that the switch may have failed and has linked mains voltage to the chassis. Of course, this should never happen because of an earthed chassis, but I would wager that we have all come across questionable, cheap, Earth connections. I often see Earth connections screwed to corrosion-resistant paint. Crazy. WARNING: The only safe way to have your equipment wired is to UNPLUG the amp, then change the fuse. If you choose to have the fuse after the switch, NEVER gamble your life by hoping the switch is still OK after a high current fuse-failure situation. It will totally spoil your day if the current that cause the fuse to blow also melted the switch contacts into the ON position.

I have high pitched squeaks coming from my 65 bandmaster, have any idea what that could entail?

@theguitaramptech

3 жыл бұрын

Hi Nick. It could be just a tube oscillation. One simple test is to gently squeeze the sides of the tube while protecting your hand from a burn. If that doesn't indicate which tube is at fault, then replace one tube at a time. If that doesn't stop the oscillation, it may be a job for a Tech. If you're in Sydney, bring it around.

I would like to ask you a question that I am curious about. When you get a vintage or any amps from the United States what do you have to do to convert the amp over to your ac power. Do you have to change power transformers or what is tge procedure. I only ask because I live in Canada where the power is the same as the United States but I am considering moving to Edinburgh, Scotland.

@theguitaramptech

2 жыл бұрын

If you’re lucky and the amp is an Export model you will just need to configure the PT for 240v. If you’re not so lucky you can screw a 240-110v step down to the base of your cabinet like I did with my Brownface Concert. When you get sick of lugging around the extra iron, replace the PT with a Hammond and keep the original. That’s what I ended up doing with mine. Good luck with your move, Michael. I’ve done a few shows in Edinburgh and I love that town.

"These brown 'Mall - A - Roy's' - they're gonna have to go . . . how do you know that? Have they drifted, are they leaking ? I understand they will, probably, some day, so I suppose better to just get it done now? The busted screen resistor, that's just a given; replacing it.

@theguitaramptech

3 жыл бұрын

That’s an excellent point you’ve raised. I am a strong believer in keeping as much original as possible. This is why I always ask my customer “what is your intention with this amp?” If they want to gig with it or record with it, then reliability and noise is my number one goal...and those Beautiful old capacitors need to go. If he is a home player, or a collector, my advice is to leave the original capacitors in place until they show clear signs of end of life. Great comment. Thank you.

@captainamerica9353

3 жыл бұрын

@@theguitaramptech , sorry if my comment was a little brash. Just about a year ago (to paraphrase John Fogarty), I won an eBay auction on a 1966 Princeton Reverb. It had been re-listed and long story short, sold for about $1,600, and it was very clean cosmetically, so I expected junk inside! But after digging it out recently to check it out ( I put it away as a project for this coming winter ) , was amazed to find a sanitary inside cabinet, original speaker, and pulled the chassis to find all 1966 dates codes. Oddly, the two wire cord looks original, but no death cap ? The wires run straight to the accessory outlet, and the old yellow wires go from there to the ground and power switch. I may just keep it as is, since I won't be using a mic with it at home. But even though someone replaced the bias caps, it looks untouched inside, original Mall - A - Roy's :-) and blue caps. Sounds good, except for a scratchy volume pot. So I am cleaning the pots with D5, and will clean the tube sockets and jacks. Almost forgot, it sounded terrible, (hum, etc.) when I got it, and had a rectifier tube marked "Made In Chian" and crappy cheap power tubes. So replaced all the tubes, and it worked, then pulled the chassis. So I agree with you, replace what should get replaced if used professionally, and do only what you need to at home. Though using a grounded plug for safety would not be a bad idea! I subscribed, BTW, love your vids and Uncle Doug's, as well. Already have a Variac (used it on the Princeton), and am getting a better Multi-Meter and a few other things IOT to do most of my own work, hopefully. Plus bought a 1966 Gibson Minuteman with a bad (cracked) 2 prong plug and missing reverb tank for fairly cheap as a guinea pig to play with. G' Day !

@theguitaramptech

3 жыл бұрын

@@captainamerica9353 I am glad you have found Uncle Doug's channel. I subscribe and am a proud Patreon sponsor of his. He is the best teacher on KZread, and he makes such an effort in his teaching videos. Check out Brads. Guitologist, too. I love Brad's honesty in his repair work, which he shows warts and all. We all go through it, but Brad shows it. I did not take your comment as brash at all. I am in 2 minds about your 2 prong cord situation. I'm in Australia, and it is quite rightly illegal here. I understand the USA traditionally didn't have an earthed lead, but in my Aussie opinion, I would DEFINITELY recommend changing to an earthed lead, and originality be damned when it comes to your safety.

@captainamerica9353

3 жыл бұрын

@@theguitaramptech , yes, I think you are right, in asking your customers what they are looking for and how far you can go in upgrades. Since my Princeton has replaced bias caps, it's no longer 100% original now, anyway. So I should go with the grounded cord. And I have subscribed to Doug's and Brad's channels. Peace

What voltage do u start with to bring it up slow . I'm in the us .

@theguitaramptech

Жыл бұрын

Hi Good names. Please don't make me watch ME again. I assume you mean bringing up the Variac voltage? I start at zero and slowly work my way up from there. We're at 240v in Australia, so I'll usually give the capacitors a little rest stop every 50 volts or so.

Is there a big difference between this and a bassman of the same year ?

@theguitaramptech

Жыл бұрын

Good question, "good names". The Bassman and the Bandmaster are almost identical. The feedback resistor is much higher in the Bassman giving it a “looser” sound. The power transformers are the same, but the output transformer is larger on the Bassman. A smaller output transformer will reduce the wattage and bass in the output. Also a smaller output transformer will have a different kind of compression, especially as the volume levels increase. I have a gorgeous drip edge 50w Bassman that hasn’t seen a gig for 10 years. Sadly, its simply too loud for the 2020’s.

Chris...hi..how are things? A bit off subject this but just a quick word about Reverb. From what I can see this is digital on most amps today inc. Fender, but do you think they are as good, is the effect as good, as on the old spring in a tank units ?

@theguitaramptech

2 жыл бұрын

Hi Vincent. Thanks for the excellent question. There is no doubt that DSP is getting better, but in the end, a great Digital Signal Processor is just trying to emulate that rusty old box in the bottom of your Fender. For me, it’s a no brainer. At a gig, I would much prefer the reliability of a DSP reverb. For home use or studio, I would prefer the rusty old box. I have just bought a Reverb DSP chip from Accutronics. If anyone is going to make a good DSP representation of their products it would be them, right? If I ever come up for air, I would like to incorporate that chip into my take on a 5E3/5F2. Between amp repairs and the videos, I should have that project nailed by 2027. 😂

@vincentl.9469

2 жыл бұрын

@@theguitaramptech I was going to say,, I don't think it's possible to link up or wire in a spring reverb tank into an amp with digital reverb?

@theguitaramptech

2 жыл бұрын

@@vincentl.9469 it’d be a challenge for sure, but I reckon I could do it. What’s the worst that could happen? I’d fry the DSP. Watch this space. 😎

@vincentl.9469

2 жыл бұрын

@@theguitaramptech it's a while since I had an amp with a reverb tank. some digital units can sound 'synthetic' at times, hard to describe, but others are very good . Don't think they'll go back to springs in a tank

@vincentl.9469

2 жыл бұрын

@@theguitaramptech Hi Chris.. not looked at your channel for a while. How are things in Sydney? you didn't end up underwater? I've seen the videos. More water than you could dream of ..

I hope they didn't recover it, it's best to have an original 20th century amp look it's age considering all of the clones and reissues.

@theguitaramptech

4 ай бұрын

Agreed. That was my advice, too. I'm not sure what happened in the end

You show in your video removing the yellow wire from the end lug of the Bias pot that goes to the Bias cap Diode section so you can get a DC reading on the Output Coupling Caps and check if they are leaking. Well I’m just learning this stuff and doing what you did on a mint 67 Deluxe Reverb almost cost me a NOS vintage set of power tubes. Without that yellow wire hooked up to the Bias pot the tubes were red plating. I smelled it, looked under the amp and saw the tubes glowing red and killed the power switch. What gives with this procedure. Am I missing something or did you not mention a step in the video for performing this test. I’d really like to know how to test these caps for leakage because if they do leak I definitely will loose these tubes, please help, thanks.

@theguitaramptech

2 жыл бұрын

Hi 60retired. I can’t recall the video exactly, but the idea is that you disconnect the low voltage side of the coupling caps from the tubes. You can either lift both low-voltage sides of the caps or as I do lift the negative supply. The bias will now be at 0v which means your tubes will be full on, so please remove your power tubes before performing this test. If you see a positive voltage on the low voltage side going to the tubes, you will have a leaky cap. It is not common for those Blue caps to leak, and your sound passes through them, so please do NOT change them unless they are leaky.

@60retired

2 жыл бұрын

@@theguitaramptech this is the link to the video in question kzread.info/dash/bejne/m6x8ubCwaZOtZbA.html and you just gave me the answer I was looking for (Please REMOVE THE POWER TUBES BEFORE PERFORMING THIS TEST). Wish you had mentioned this important step in your video obviously it’s a major deal when preforming this test, these matched vintage RCA 6L6GC Blackplates are going for big dollars now days. I do thank you and appreciate you replying so quickly, maybe now I can perform this test correctly. Those coupling caps are all staying unless any are leaky.

@theguitaramptech

2 жыл бұрын

@@60retired you have raised a very good point. I don’t show every step of my already long videos. Please learn from my videos, and those of my KZread colleagues, but I would not recommend using them as step-by-step formula. Valve amps are deadly, and I am concerned for your safety. Can I ask you a question? Can you explain why 0V on the control grid of a cathode biased tube is correct, but 0V on the control grid of a fixed bias amp will red plate the tubes? If you are not sure of the answer, please do more learning. It’s a fun journey!

@60retired

2 жыл бұрын

@@theguitaramptech I know were you are going with this question and for good reason. On a Fixed Biased amp the cathode has a negative charge and the plate has a positive charge, opposites attract so the negative electrons flow to the plate. The Grid is suppose to control the flow of electrons from the cathode to the plate. If you don’t have enough negative voltage provided from the Bias pot the electrons flowing get out of control and the plate gets very hot and glows red. I basically understand how it works maybe not the best explanation. When I watched the video the first time and saw you undo the yellow wire from the bias pot to check the cap voltages my first thought was the tubes, but I figured you must know something I didn’t and I didn’t give it anymore thought, my mistake because I know better. I only work on my own amps and have no interest in working on anything other than Vintage Fender fixed bias point to point wiring amps. I’ve been working on them since around 2007 and have learned a lot since. I keep numerous tech notes to refer to and I faithfully follow the one hand rule when working on them. I have acquired a number of testing equipment to help perform servicing and even have a medical grade Toroid isolation transformer to provide some safety incase I get sloppy although I don’t just rely on it to save me. I have an oscilloscope for signal tracing a circuit and I’m aware that once the probe ground clip is attached it creates a ground reference even with using the ISO. When using more than one probe the same grounding point must be used to prevent another ground potential. I use a very unique Bias meter that displays the mA, plate voltage and watts for both tubes at once. It’s one less time you have to work inside the chassis when its powered up so safety is always number one. Still have more to learn but I have come a long way and feel very confident and comfortable working on these old amps.

@theguitaramptech

2 жыл бұрын

@@60retired Thanks for the reply. I feel much better now. You had me worried for a while there. Another suggestion for you. When you are working on a problem, I would suggest removing any valuable tubes and substituting cheaper Testing tubes until you're ready to bias. I usually don't have ANY power tubes plugged in until I am happy with the voltages, especially on pins 3,4 and 5 (on octal) or 7,9 and 2 (on EL84). I fully applaud your safety measures. I still use an Iso, and I even wear rubber gloves occasionally. I work alone so a hit of 240VAC or 450VDC may stop my 64-year-old ticker with no one around to call the ambo! :) Enjoy your journey.

But Saint Peter 😂

@theguitaramptech

8 ай бұрын

HAHAHAHAHA!

Typical burnt screen resistors

@theguitaramptech

3 жыл бұрын

Yep. It's not uncommon.

Guys, get jj power amp tubes or else get nos. What are you doing. Also, definitely go vintage rca with your preamp tubes.

@theguitaramptech

4 ай бұрын

Good call, but I doubt many people can afford to buy NOS RCAs these days. Used vintage tubes are a lucky dip. Most good ones have been kept by the seller, and we buy the microphonic leftovers.

@CoolhandLukeSkywalkr

4 ай бұрын

@theguitaramptech the rca used off ebay us better than the new tubes

@theguitaramptech

4 ай бұрын

@@CoolhandLukeSkywalkr I am glad that you have had better luck with used tubes than I have. Well done

@CoolhandLukeSkywalkr

4 ай бұрын

@@theguitaramptech You should try cleaning the old pins. If they are too noisy

@theguitaramptech

3 ай бұрын

Yes, I routinely clean the pins and the sockets in the tube base. I edit out SO much of the repairs, and still my videos are long. Thank you for sharing.

Metal film resistors better

@theguitaramptech

3 жыл бұрын

Thanks Ian. I prefer them, too, but I won't change out carbon comps unless they have either drifted over 15% or started making that annoying crackling sound when used as plate resistors.

@moodyga40

3 жыл бұрын

Need more videos

@theguitaramptech

3 жыл бұрын

@@moodyga40 Thanks, mate. I have so many customer repairs to do, it's challenging to find the time for making videos. Less sleep is the answer!

Hi Chris. What band were you in or what was it you did around the world. Before you went into amp repair? Dwight.

@theguitaramptech

2 ай бұрын

Hi Dwight. I had a company called Teammania which performed events around the world that I wrote. They often used live music but other shows did not. Sometimes I would bring performers with me from Australia, but most of the time I used Americans (or Brits etc) for the shows. These talented people have become lifelong friends. When I was 17 my amp blew up. I did quite well at high school and my Greek parents naturally wanted me to do medicine…but I had an amp to repair, Dwight, so Electrical Engineering it was. When I started my shows in the USA, my Atlanta lawyer suggested I register them with the Library of Congress. I did. My IP was still blatantly stolen. Oh well. It was great for the 20 years it lasted.

@dwightbehm2886

2 ай бұрын

@@theguitaramptech well Chris what every that was in your life for those times must have been wonderful. And a good accomplishment. With the way your are and your patience with things you probably would have made a good doctor as well. As google tracks my interests in electronics amp repair on utube it offered one of your amp repair videos so I tapped on it and watched. In my life at one time I was a specialist in the repair or replacement of automobile automatic and manual transmissions back in the 80s and in the 1990s. It wore me out. So I had to learn some Automotive Electronics and electrical. In that field there was a lot self-taught and in other electronics like amps. It's very nice to find people like you sharing knowledge. It renews my faith a bit. I have talked to some ham operators in Melbourne Australia many moons ago by two way radio direct long distance a lot of fun. Your new friend. Dwight.