It amazes me due to how much you know and what you do to amplifiers and guitars. The Best there is out there.

@guitarc.p.r.9675

4 жыл бұрын

Thanks Jody. I am just a guy with a tool box and some experience.

@jodystarkey4213

4 жыл бұрын

@@guitarc.p.r.9675 your a good guy and modest. The best out there

Awesome just awesome

Subscribed to your channel

Hi. Very interesting video, just wish it was longer with more detail. I just picked up a very early 2204 from 1981. It has very low output/volume compared to another 2204 I own which is freakishly loud. Also it seems to be clipping and getting odd volume drops. I’ve checked the tubes, filter capacitors, bias, drawn a blank. Any ideas?

@guitarc.p.r.9675

3 жыл бұрын

Funny you should say that. I am trying to keep the videos short. 6 minutes seems to be the sweet spot. I can see the view lengths and click thru rates. I have even been told no one will sit through a longer video. Some people just do not have the attention span. Again, I repeat, these are not how to videos. Volume drops in 800s are usually related to bad solder joints or bad connections in the low sensitivity jack. The clipping, and low volume I have no idea with out it on my bench. I also just approved your comment to AJ. A properly modded 800 is amazing maybe you just have not heard one yet. Thanks for watching, I appreciate it. I hope you will stay.

Would be interesting to know why the customer wasn’t happy with the original amp and also what mods you did and why?

@guitarc.p.r.9675

4 жыл бұрын

It is very simple. I mentioned in the video the amp was old and tired, he purchased it "as is" and sent it directly to me. He had not even played it. It had very low volume and needed help. He also owns another that we had rebuilt to serve his needs. He wanted this one to be slightly more aggressive in a two amp setup. Everything was done for a specific reason, either for tone, response or reliability. The mods are also explained in the vid. Thanks for watching!

I was wondering about disconnecting the low input, why exactly? I have an old Marshall jcm800 4010 combo and want to thicken up the preamp a little, what would be a reversible mod? I swapped out the speaker, it was a Celeston Wolverine, really harsh sounding, for an Eminence DV-77.

@guitarc.p.r.9675

2 жыл бұрын

The reason I disconnect the low jack, is to eliminate the intermittent losses and drop outs, tone cuts etc. I consider the switching jack a weak spot in the design. The older hand wired models are easier and totally reversable, the board mounted pot models are a little more difficult. Two suggestions...1 have you chamged the Power supply caps? 2 remove R4-C5, replace R4 with a jumper. This will take the super bright out of it. You can also just jumper the hot contacts on the low jack to disable it.

@charlesb7831

2 жыл бұрын

@@guitarc.p.r.9675 Interesting, I have a friend of mine who's an amp tech, he does most of my stuff. I do my solid state stuff , but not tubes lol. I have an older tube tester so I keep on top of my tubes. I know the big caps are not original, but it wasn't me that changed them. I've had the amp for 13 years. It's a 1989 jcm800. In great shape otherwise. I definitely have to look into this more. I didn't want to mess with the originality of it much and I've seen some really butchered jcm800s that cost a small fortune to restore afterwards. Hence why I've been reluctant to mess with it. Very much appreciated!

2:30 i bought a dsl100 jcm2000 recently (GC Used site) it had a 20amp fuse in it!

@guitarc.p.r.9675

2 жыл бұрын

That is why I have the fuse rule. I have a not-so-little plastic container on the bench containing years worth of grossly oversized car fuses etc. removed from toasted amps. Sometimes, I show, and shake it for a customer when I am trying to make this point. I have seen a LOT of dead transformers, burnt boards, and such from these audacities.

@guitarc.p.r.9675

2 жыл бұрын

Also reminds me of one of my favorite clueless customer comments,,,,,,"Well a fuse is a fuse, ain't it?"

I’d really like to know what you changed exactly (values) and why….Any chance I could get that info somehow ?

@guitarc.p.r.9675

2 жыл бұрын

When I get time I will review the video and write you an essay.

@guitarc.p.r.9675

2 жыл бұрын

Ok I took a few minutes to refresh myself. That amp was done a couple years ago. Before we get too far into it I must mention, This amp was modded to suit the client, it may not fit everyone. I have worked with this friend and client for about 30 yrs now. It is a little more aggressive and darker than a std 800. First All the electrolytic caps were replaced. For tone and reliability. Then the transformers....We had been down this road before with his previous amp. The improvement was so apparent in the first amp, when the second one came up He told me "there is no need to do it at all unless we change the transformers like in the first one". Now about the mods. I disabled the low input, this is because if they get dirty the volume will drop or be intermittent, and most people just do not use them anyway. The input resistor was changed from 68k (which I believe to be a common undersight in amp design and should be 33k to begin with) to a 10k. This is to increase sensitivity. The 470k resistor between the 1st and 2nd preamp stages is reduced to 220k and the 500pf cap across it removed. This loweres the series resistance between the stages and removes some of the extreme highs. The bright cap was also removed from the gain control. The 470k resistor feeding the tone stack driver is left stock but the cap across it is changed to a 500pf high quality silver mica cap. This leaves the highs intact but smoothes them out slightly. The 33k slope resistor in the tone stack is changed to 56k, shelving the stack a little higher and takes out any muddiness. The treble cap was also changed to a high quality silver mica. A couple bias resistors were changed to adjust the bias range. The bias feed resistors were changed from 150k to 220k. As I remember the tubes were biased @ 34ma ea. plate current only. Hope that clears up your question. I also suggest checking out AG's comment here. Thanks for watching.

I thought the early 800s had flying leads to the pots and not board mounted pots like this one?

@guitarc.p.r.9675

3 жыл бұрын

You are right the earliest ones did, the one in the video is a second generation but still early. The 800 idea began in the mid 70's with the first master volume amps. Some of the early 800s were JMPs in transition. I actually have a salvaged board from one of the early ones to show people what they looked like, still a pc board but with external jacks and pots. There was a lot of changes going on early in the evolution of the 800s.

You couldn't find a schematic for a 2204? Also, why not address your component swaps a little more?

@guitarc.p.r.9675

3 жыл бұрын

Yes, I have a schematic for a 2204, actually I have about 20,000 schematics. most cases with an 800, I do not need one. What you missed was the quick sketch was of the mods done to his first amp. I did that the last time it was in so it could be duplicated. Plus if you look at that sketch you will see what most of the mods were. I did change a couple things in the second one to make it slightly more aggressive per his request. Again these are not how to videos. If I tell you everything it just opens up room for more troll arguments, and liabilities from amateurs. If you want to see what I mean look at the comments on the 900 vids.

So I would just like to respond to some of you concerning this amp that was duplicated here. I am the owner and just want to say, my ear tells me that mercury suits me best. But I am demanding and don’t want a crutch, that way its all mine. I play a variety of music which is why I have a variety of amps but in my years love it loud so understand we are not talking about bedroom tone here. There are many things that I judge power by as it concerns sag, clean, how overall a tone will hold in a note range, and lastly how what is transferred from your hands to your ears from your amp. Charlie has for years made sure that happens. He has tailored everyone of my amps to suit my demands. And I am picky. As an example he rebuilt a pro-reverb for me over 20+ years ago. He had to re-bias a tube set for me as groove tube is no longer in business (for quality and matching) that is. During that same time he had to change resistors to finish the job and fix a ground as outdoor gigs are not so good on an amp due to humidity (ground plate lite corrosion). Other than that, no problems what so ever. Matter of fact, nothing he has fixed or rebuilt for me has ever disappointed nor has it ever let me down and everything I own and gig with is pure tube power. These two Marshall’s I run in stereo. I also run a 62 band master and a 67 bassman with either of these Marshall amps in those stereo rigs with regard to 4x12 setups. I have to tell you, those fenders kick those Marshall’s ass and don’t bow to volume either. And yes, he built those as well. I noticed on here that there are some comments as to the validity of his work. Or when does a Marshall stop being a Marshall? Well those are copy’s of x or y for power. Well let me say, it will never be a Marshall until you learn how to use one. When mods are spoke of here they are pointed out after the build, you did see the pointer stick? The power you notice is the most important part of your amp. The circuit only places the demand, somethings gotta answer. Call Patrick at Mercury Magnetics, let him know what your demand is. Then go find a guy that will meet your needs. Doesn’t matter whom. For me Charlie does it right, not to mention he do 11 with a simple circuit then to infinity without the use of OP AMPS or a cascade. Look it up. Thanks Charlie P.S. where my Trainwreck

@guitarc.p.r.9675

4 жыл бұрын

Thanks A G Yes, there is your amp! Sorry Man, I don't know 'nuthin about no Trainwrecks

@vintagesound8112

3 жыл бұрын

Hello A G. As you’re the owner do you have any sound clips of this amp? My 800 is stock but I’ve yet to hear a modded one that sounds better, I suppose it’s kind of perfect the way it is. But well each to their own.

@AG-hq8jy

3 жыл бұрын

@@vintagesound8112 yes I have some sound clips for you. Although it may be less than your likeing as you are lucky to have a stock 800. But as you said, to each his own. So you can check out the clips on Van Halen diver down, ac/dc for those about to rock, Jeff beck blow by blow, allman brothers (pick one) ZZ Top rio grande mud through fandango and tejas, thin lizzy pick one, humble pie pick the live at the Fillmore, Led Zeppelin before and after houses of the holy and so on. But that is just to my own, maybe we should POSE it to the FORUMS...then we can really pick apart what year and what amp was used and how wrong I am. It’s the tone that has permeated the planet. LOL Have fun with that. How about you post some clips of yours.....

You should have gotten blue transformers to match the caps. Just saying...

@guitarc.p.r.9675

4 жыл бұрын

I know....too bad they do not make the caps in red. We all know the red ones sound better! :)

@Kenman540

4 жыл бұрын

@@guitarc.p.r.9675 The best!

Would you sell me the old Transformers sir ?

@guitarc.p.r.9675

4 жыл бұрын

Sorry, but they are kept by the owner.

Why remove low sensitivity input.

@guitarc.p.r.9675

4 жыл бұрын

Most people do not use it, and it is a weak spot. If and when it corrodes it will cause loss of volume intermittently, because your signal from the first gain stage passes through it. It can also cause a static chatter. It is not such a big thing if you are just just a home jammer, but in this guy's case he is a working player, reliability is essential....and he is in Florida, I am in WV.

@CrowemagModelWorks

3 жыл бұрын

@@guitarc.p.r.9675 How did you disconnect that on a PCB mounted unit? I am interested in doing this on mine. Thanks.

@guitarc.p.r.9675

3 жыл бұрын

@@CrowemagModelWorks You must un-solder it from the board and install a jumper.

@guitarc.p.r.9675

3 жыл бұрын

@@CrowemagModelWorks Actually I cut the traces and leave the jack in for mounting. Then add a jumper.

@CrowemagModelWorks

3 жыл бұрын

@@guitarc.p.r.9675 where do you connect the jumper? Does this effect the sound of the high input at all?

If you make good content and target the right viewers the view times will be much higher. For guys interested for the technical and theory and build and repair part of it they want to see the whole process and will watch. The instant gratification viewers that just just want a sound clip may not watch . Think the serious amp community far out number the trolls and surfers. Guess it depends on you and what you are looking to get out of it as a channel. This particular video was basicly useless for both .

@guitarc.p.r.9675

2 жыл бұрын

You are entitled to you opinion. I will take your comments under advisement. I am learning that no matter what is said or done, the shouters of the ney, and pickers of the nit will comment on anything from transformer choices to part selection. Then there are always going to be the ones that want you to spoon feed them all the free info they can get. Then question it. The Marshall comments have proven that.

@vancenewland6549

2 жыл бұрын

@@guitarc.p.r.9675 like your channel and content, just saying when you say here's a amp here's what I'm going to do and here it is done in 16 minutes.....

Were the transformers even bad??? At some point this is no longer a Marshall.

@guitarc.p.r.9675

4 жыл бұрын

No the transformers were good. However the replacements made a huge difference. We did his other one in stages several years ago. He mentioned it would reach a certain point and tonally hit a wall. We replaced the transformers and he was thrilled. When this one came in he commented it is not worth doing unless we change the transformers first thing! Again he is a pro player and we are fitting a need for him. Tone, reliability and response are the main goals. Funny you should mention "no longer a Marshall" it certainly is just with a few tweaks. Thanks for watching. Transformers are the beginning and end of and amplifiers function, the most important part but the first to be scrimped on

@jaycee30865

4 жыл бұрын

Guitar C.P.R. I figured drake and dagnall to be the end all be all for Marshall; what did they ever use otherwise? Is the mercury copying a Woden (I know from Vox) or something? I don’t know what Marshall used back in the day. Too stiff of output iron can be grindy in my experience, and mercury definitely overbuilds for fender amps. Takes out the sweetness. And the paper bobbin of heyboer sounds way better than mercury in a 50w comparison of 4 or 5 transformers posted somewhere out there. Check it out.

@jaycee30865

4 жыл бұрын

Guitar C.P.R. It’s on a page called paper vs plastic at the classictone site.

@jaycee30865

4 жыл бұрын

Guitar C.P.R. I have a 2204 that functions perfectly but after a while it starts screeching. Seems like you can fiddle with the input jacks or just turn it on and off to make it go away. I have read about Marshall using insulated wire between the second half of the first valve and the PCB. Something like that. But I’m not sure that’s the issue. Have you ever run into this yourself on JCMs? 

@guitarc.p.r.9675

4 жыл бұрын

@@jaycee30865 I have seen it. Thanks for the comments, everyone is entitled to an opinion.