I did the same Dietmar mod. Mine's still going strong and sounds great! I did upgrade the main PSU caps as well.

@gratisnepkut This is the Lampizator circuit. Thanks for watching. Happy listening!

Very impress, hope to see more video from you about Hi Fi. Thanks

good job

Боже, какая радость! Спасибо тебе Just Vlad! Лайк лайк лайк!

Well I have a different idea about modification in my mind. If it works out Ill publish. I will use 6SU7 (better 6SL7) for the first stage one section per side. It will be loaded with constant current source (LND250?) directly coupled to 1 section of 6sn7 cathode followler with current source on cathode. This will give wide bandwidth. The driver tube will be 6AH4GT with again current source on plate and large cathode resister to match the voltage of the 6SN7 cathode to its grid (direct couple) This will be parafeed to a 5k:5k interstage transformer. The primary is hooked up between plate and cathode of 6AH4GT tube via a capacitor. The secondary is connected between 845 grid and bias. Edcor transformer makes inexpensive 2.5 watt interstage transformer at $13. The interstage transformer will be inverted so some distortions can be cancelled out. For current source you can use IXCP10M45S.

After 2 months of waiting I received two bricks in the package, not the amp. I filed a complain with ebay and got my money back. I guess, I will be building my own amp from scratch. I have a pair of 845, 8k se transformers capable of 120ma dc, pair of 801 for driver (mu of 8), interstage transformers and pair of 841 tubes (mu of 30) for voltage amplification. All DHT tungsten filaments. Its gonna take some time to build it.

Thanks buddy

Is there any upgrading for the Music angel 300B XD850III?

If you want really good sound from 845, the dc resistance to grid must be low while the ac resistance should be near infinity. Direct or interstage transformer coupling are the only options. Direct coupling is near impossible for 845. Interstage transformer is the only viable option. given the space available only small interstage transformers (edcor 10k:15k. 2.6 watt) will fit. They cannot handle any dc current so must be ac coupled (Parafeed) to driver tube. driver tube must have high voltage and current capable. I like 6AH4GT running at 25 ma and 220v plate to cathode. It must be ccs loaded with 10m45s depleation mode hv mosfet cascode with a low dropout linear regulator configured as current source. Front driver can be any triode with mu of 10 to 30. I like 76 triode for linearity. Again ccs loaded. total max gain with ccs load is 13.5x8x1.2 which is bearly enough. I have ordered a music angel from ebay but have not received it yet. I have ordered most parts for redesign. If i am building an 845 amp from scratch i will use 841 (VT-51) then 801 or 10Y to 845. all ccs loaded and parafeed transformer coupled. Good iron and tube rectification. But this will cost many thoudands $ and i cannot afford it. Thats why music angel.

it will run them just fine as long as they are high db speakers. 95+db. mine are 150w but 104 db and it runs them loud at only half volume.

Nice job, actually you are skilled. Anything you can add to the video even if it's an update saying all is well?

What's the difference between the MkII and MkIII? They look identical but I can't find any info.

привет, do you know if this amplifier has enough "oomph" nice sound an power, спасибо

Sorry, wrong button, just wondering where did you buy this amp?and how much? Thanks

Нормально так, ролик на инглише и раз в конце Русские песни =))

Hello , I have the same amp but I wanted to tweak the circuit for ages but lacking the confident to do so. Are you able to email me the the stage by stage to complete the mod. A list of the parts that are needed so that I can go shopping. You mentioned the power supply resistors were over heating, what is your final solution to this issue?? Please help and I wanted to make the music angel sing. Thanks.

Hey could this amp run speakers rated at 60 watts at 6ohms

Die sparen noch an 10 Cent Lötleisten.Hat der Netz-Ein Schalter auch nur eine Phase ?

песня Светланы Островской "ДЕВЯТИЭТАЖКА"

Hi Vada3D, do you still own your Music Angel 845? I have an M.A. KT-88 which I modded successfully and consider buying this one. Did you connect the ground of the power cord entry? On my amp it was not connected, since yours is running at close to 1000 Volts a connected ground is a safe idea Thanks for the vid, it's a great motivator.

Good job guy

song name?

Helps me out: geni.us/JustVlads

You should just scratch build a st 70 dynaco. After fifty years those still run with the best.

Vada3D can you mod for me too? i knw nothing about electronics and find nobody can help me out.

Uhm.. And also.. The name of the ong please :D

AAAH Russian music... I hear it all the time... Wife is Russian.... Sounds good. How much did this amp cost? How many watts? What are the output tubes?

Alla Pugacheva

Was ? Kohleschichtwiderstände.Da wurden 0.1 Cent gespart.

Hil.

Good, thx. Do you like Russian music?)

the second lamptizor started to remove grid stoppers he lost my respect.

4 Ohm 8 Ohm Fake

I do not like the mod, as I do not like the whole amplifier nor its toppic. This "amp" uses a transmitting tube. So to tear some resonable watts out of its outlets it needs driving current! Yes - the 845 needs to be driven with resonable signal grid current. Witch ,of course, the "amp" will not do. As the grid resistance of the 845 drops from serveral 100k to somwhere near 10k the driver just cuts out.... You´ll need at least any sort of interstage transformer to drive the 845 propperly. Messing around with the grid stoppers simply does not overcome the problem, as it lies in the electric "design". Removing the GS-resistors produce some new problems. Read some serious tube circuit design books first, then do some modifications when knowing what you´re doing.... Grid stoppers are in there to prevent the amp to oscillate in th RF-band frequencies.... To be honest this all is only wasted money!