Circuit board looks pristine;no bulging of electrolytics.I was wondering if it's just a bad driver tube?The cicuit diagram capacitor values don't seem to reflect the reality of the circuit board.The amp ran faultlessly till this;sounded great.
I can't read the values of the small electros at the rear of the board.
This is my first valve amp and I'm only learning(scared of high voltage).
coit
I can't read the values of the small electros at the rear of the board.
This is my first valve amp and I'm only learning(scared of high voltage).
coit
I made a schematic for the amp as I received it. The items in red differ from the "official"one posted for this amp. The smal caps are probably the 220uF caps for the 6P15P tubes (C4 in the picture) and I should have drawn 1 more as on the PCB there are 4 (2 per channel)
With the 250V ac setup of yours, I think the B+ could be higher than the 284V measured by another forum member. Would be interested what the voltage is on pins 9 of the power tubes. In the standard pentode configuration that voltage will be much higher than the max allowed grid voltage of 150-200V as found in the datasheet.
And yes, be careful with these high voltages. Better not risk anything.
Maarten
An externally hosted image should be here but it was not working when we last tested it.
With the 250V ac setup of yours, I think the B+ could be higher than the 284V measured by another forum member. Would be interested what the voltage is on pins 9 of the power tubes. In the standard pentode configuration that voltage will be much higher than the max allowed grid voltage of 150-200V as found in the datasheet.
And yes, be careful with these high voltages. Better not risk anything.
Maarten
Yes, I meant to say that in the original drawing of Suppo they have 6 caps of 220uF. In reality there are only 4 present of 150uF each en 2 empty slots on the board. So these light ones are NOT present and I looked for a way to indicate that components are not present.
Apparently not entirely clear ... sorry
btw, this is what it looks like now. I've stopped making mods as I do not trust the safety of this amp completely and will start making my own. Amp is now in triode mode, I added grid resistors and CCS cathode bias. Also stepped attenuator. Modified parts in blue. Not shown (obviously) is new IEC inlet with fuse, new better power switch, resoldered(/insulated) wires and PCB cleaned as small metal parts and excessive solder were on the board, at places I did not like it.
An externally hosted image should be here but it was not working when we last tested it.
Maarten
PS. I corrected the drawing originally posted and now there is a C4 a and b, could not edit the text anymore.
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Maarten,
Thanks for the effort in capturing the Suppo GV-x schematic in its "real" form. This is really helpful. I have to say that my Suppo GV-1 is still going strong once I installed the stock 6P15P tubes back in after my Genelex Gold Lions went out. A buddy of mine did similar component replacements as mine, only he used Auricaps in the coupling capacitor positions. He really loves the sound quality he's getting with his Fostex F120A bass reflex monitors.
How would you compare the sound of your Suppo amp in triode mode versus the original (ultralinear?) mode? I'm hesitant to switch to triode mode, because I am content with how it sounds now, but if triode mode is better, I'll mod it per Oneyed K's recommended path.
The power transformer cover might be held in place with an adhesive. To remove the adhesive, you would have to soak the transformer cover in some Acetone or some other strong adhesive solvent, but I wouldn't advise this as you'd probably damage the transformer. Why do you need access to the power transformer?
I agree with Gorgomat that a capacitor probably fried. If you aren't experienced in safely working around tube amp circuits with electrolytic caps carrying up to 400V, you should probably get help from someone who is experienced to help you out.
Coit, that the best idea around, how to do!
for Rhing: keep in mind, that for triode mode the output transformer needs a lower impedance to perfom at optimum. maybe you may try for that the UL taps of the output
transformer first. we dont know the taps impedance, but its worth a try anyway.
for Rhing: keep in mind, that for triode mode the output transformer needs a lower impedance to perfom at optimum. maybe you may try for that the UL taps of the output
transformer first. we dont know the taps impedance, but its worth a try anyway.
maybe you may have a look here, workmanship looks quite good:
À·Æ¶ûµç×Ó¹ÜÒôÏ쳧
dont know how they ship, or if they ship to other countries
À·Æ¶ûµç×Ó¹ÜÒôÏ쳧
dont know how they ship, or if they ship to other countries
Looks good, indeed, too bad I don't read Chinese...
/edit: http://www.raphaelite.com.cn/en/index.asp
Hmm, schematic is probably the only readible part of that website for me
, but I'm sure you do not have that problem. What are the prices in USD Steve, and where would we be able to find shipping info...?
Maarten
alternative
so, just click on the pic, even a schematic is submited a bit below.
how to figure out shipment or the prices, just let me search with my chinese staff here. I will inform you about the results. no need to learn chinese.. as i am quite busy at the time, pls. remind me by an email or so if i delay:
fischer.stephan@gmail.com
so, just click on the pic, even a schematic is submited a bit below.
how to figure out shipment or the prices, just let me search with my chinese staff here. I will inform you about the results. no need to learn chinese.. as i am quite busy at the time, pls. remind me by an email or so if i delay:
fischer.stephan@gmail.com
Hello,
On the suggestion from OneyedK, I finally got around to install new bypass caps in my Suppo EL84 amp. Up to that point, my amp had performed flawlessly. I'm very happy with its performance. I replaced the 4 220uf caps with 2 large 1500uf 35v nichicon caps. While I was in there, I decided to solder in one .012uf silver mica caps in parallel with each of the k40 coupling caps. After a few hours of warm up, I gave it a listen. There seems to be improvement. Clarity and speed was better and the overall sound was more relaxed/smooth. That sounds contradictory doesn't it? It's tough to explain but the word creamy comes to mind. Anyway it's still too early to make difinite judgements the new caps need more time to burn in, so I'll just leave it at that for now. Now, if I can get someone to describe the sound changes in using the CCS over the cap/resistor, I may try it. After this I may have one more mod to make: the triode mod. Again thanks everyone for the information provided through these posts.
Regards,
David
On the suggestion from OneyedK, I finally got around to install new bypass caps in my Suppo EL84 amp. Up to that point, my amp had performed flawlessly. I'm very happy with its performance. I replaced the 4 220uf caps with 2 large 1500uf 35v nichicon caps. While I was in there, I decided to solder in one .012uf silver mica caps in parallel with each of the k40 coupling caps. After a few hours of warm up, I gave it a listen. There seems to be improvement. Clarity and speed was better and the overall sound was more relaxed/smooth. That sounds contradictory doesn't it? It's tough to explain but the word creamy comes to mind. Anyway it's still too early to make difinite judgements the new caps need more time to burn in, so I'll just leave it at that for now. Now, if I can get someone to describe the sound changes in using the CCS over the cap/resistor, I may try it. After this I may have one more mod to make: the triode mod. Again thanks everyone for the information provided through these posts.
Regards,
David
after all, i like to suggest "breadboarding." its fun to make the own amp from the scrap with some calculations. i just put everything on a wooden board, using experimental PCBs, make a nice wiring, and, that thing, if nicely done, can also look good. pure function as a design. this kind also makes i easier for any improvement ( modification is not a good word always = means, i know it better ). this amp is very personal and individual and does not look like from a standard(scrap) manufacturer, which hundreds of people are using. lets find the way back to the REAL DIY!
I emailed them 24 hrs ago but no reply yet.
The order page shows a silver amp with hidden/tucked in tubes. But when I click on paypal it shows the golden amp with tubes on outside. Which version is being sold now? Can the maker or some recent purchaser want to share information?
Also, has the grounding been done with the recently made amps?
The order page shows a silver amp with hidden/tucked in tubes. But when I click on paypal it shows the golden amp with tubes on outside. Which version is being sold now? Can the maker or some recent purchaser want to share information?
Also, has the grounding been done with the recently made amps?
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