Thank you for sharing. Another great video! Hey, imo, the distortion sounds so much better now than in this previous one on this amp. Would just that new lead dressing attribute to that? I never stop learning things watching your videos. Ty. Jim
I thought it might be of interest to you that an early version of this amp does indeed use discrete transistors for switching and has twice the filtering too. I had a early 1983 (Jan 27) come across my bench that, which is all to common, was heavily butchered. The exact schematic for that version is made of unobtanium but, the schematic for the 4210 50W Reverb Combo from that era showed the early switching circuit and was enough to guide me through the repair. I hope this information is helpful to you in the future. Best Regards
There's a issue correction note from Marshall for earlys 2205 & 2210 to fix the channel bleeding. A 220nf cap between CA3046 pin 8 and Ch.1 MV center lug. Maybe it worth to check!!
Try to get some Vishay/ERO/Roederstein MKT1822s in replacement for these white box caps. They fit precisely and fit audibly better into a Marshall circuit then WIMA, Phillips, YouNameIt ...
I have watched your videos for several months,, I find them very interesting, Can you tell me if you have ever encountered a mono price stage right 50 watt combo ? After watching videos on far more expensive amps fender blues jr. Hot rod deluxe and some of the other pricey amps. I have read a lot of reviews on the Stage Right amps and they seem to get good reviews! Thanks in advance.
If I understand you correctly that one white cap is causing noise to leak into the drive channel. Wouldn't the mean that it is leaking DC? I remember working on one of the first versions of this amp and it used transistors for the switching circuit, and had red LED's instead of a bridge rectifier. Trace Davis told me that if you remove the led's there will be a LOT less gain.
Yes, absolutely. There should just be an audio signal here, the DC was already blocked upstream. They probably used 250v caps because they were already used elsewhere on other products (BOM simplification).
Sir. Stop with the amps at least for today. This is probably my favorite of all the Marshall's but right now is time for the missus Psionic Cheers from Canada
She had work to do too. We just had dinner and watched the new Star Trek. Next up, finishing Moon Knight. Then I have something potentially cool lined up for tomorrow...
Hello Sir , would it be possible for you next time you get one on your bench to explain why so many of them had channel bleed including my 1989 even after it was revised by Marshall in 1987 or around and what was causing this issue ? Thank you for your awesome channel !
Oh, it happened. Today I roasted two spatchcocked chickens on the grill, made a pilaf, roasted brussel sprouts, grilled corn on the cob, and finished it up with coconut cake and coffee. And sent mom home with a bouquet.
Truly one of the less impressive channel switching circuits. Whenever I have a customer in who's bought one, inevitably the question of 'why do the channels bleed into each other' comes up and having to explain that it's pretty well going to always be like that.
Thank you for sharing. Another great video! Hey, imo, the distortion sounds so much better now than in this previous one on this amp. Would just that new lead dressing attribute to that? I never stop learning things watching your videos. Ty. Jim
Happy Mothers Day greetings to your better half, from all of us. 🌷
Thanks man!
I thought it might be of interest to you that an early version of this amp does indeed use discrete transistors for switching and has twice the filtering too. I had a early 1983 (Jan 27) come across my bench that, which is all to common, was heavily butchered. The exact schematic for that version is made of unobtanium but, the schematic for the 4210 50W Reverb Combo from that era showed the early switching circuit and was enough to guide me through the repair.
I hope this information is helpful to you in the future.
Best Regards
Thanks! Yup, I've had a few. Always fun to go schematic diving to find something similar.
There's a issue correction note from Marshall for earlys 2205 & 2210 to fix the channel bleeding. A 220nf cap between CA3046 pin 8 and Ch.1 MV center lug. Maybe it worth to check!!
This amp already had that from the factory along with the two added 10uFs.
The 2205 & 2210 have always had channel bleed & switching / relay issues especially the older they get.
Try to get some Vishay/ERO/Roederstein MKT1822s in replacement for these white box caps. They fit precisely and fit audibly better into a Marshall circuit then WIMA, Phillips, YouNameIt ...
And you definitely peeled that onion to the core.
I have watched your videos for several months,, I find them very interesting, Can you tell me if you have ever encountered a mono price stage right 50 watt combo ? After watching videos on far more expensive amps fender blues jr. Hot rod deluxe and some of the other pricey amps. I have read a lot of reviews on the Stage Right amps and they seem to get good reviews! Thanks in advance.
If I understand you correctly that one white cap is causing noise to leak into the drive channel. Wouldn't the mean that it is leaking DC? I remember working on one of the first versions of this amp and it used transistors for the switching circuit, and had red LED's instead of a bridge rectifier. Trace Davis told me that if you remove the led's there will be a LOT less gain.
250V caps to ground out the volume knobs? I'd be curious at what the schematic looks like. I'd think you could get by with a lot less.
Yes, absolutely. There should just be an audio signal here, the DC was already blocked upstream. They probably used 250v caps because they were already used elsewhere on other products (BOM simplification).
Yeah, but it's a matter of lead spacing on the board too.
Aaaand I misread them. 100V caps. Still.
Sir. Stop with the amps at least for today. This is probably my favorite of all the Marshall's but right now is time for the missus Psionic
Cheers from Canada
She had work to do too. We just had dinner and watched the new Star Trek. Next up, finishing Moon Knight.
Then I have something potentially cool lined up for tomorrow...
Hello Sir , would it be possible for you next time you get one on your bench to explain why so many of them had channel bleed
including my 1989 even after it was revised by Marshall in 1987 or around and what was causing this issue ? Thank you for your awesome channel !
Thanks Lou! I'll try. It's a very imperfect circuit even when working correctly.
@@PsionicAudio Really appreciate Sir !
You're the best !
Are pcb Marshall’s good?
Accountants building amps...😐👎
Thanks for opening my eyes and ears😎👍❤🖖
Man I wish I could find someone to work on my VHT heads. They sound so plain.
What happened to the super grandiose grocery trip?
Oh, it happened. Today I roasted two spatchcocked chickens on the grill, made a pilaf, roasted brussel sprouts, grilled corn on the cob, and finished it up with coconut cake and coffee. And sent mom home with a bouquet.
@@PsionicAudio Today is also National Coconut Cream Pie Day. Close enough with the coconut cake. 👍
@@PsionicAudio Well Done
@psionic_audio lol you would probably have a successful cooking channel, I'm sure the same perfection of execution was transferred
@@PsionicAudio Thats a job well done, sir!
Truly one of the less impressive channel switching circuits. Whenever I have a customer in who's bought one, inevitably the question of 'why do the channels bleed into each other' comes up and having to explain that it's pretty well going to always be like that.
Yeah, a definite miss on Marshall's end there. But it shouldn't hum/buzz.