Heaters don't light? - do you have any voltage to the heaters?
Do you have voltage on plates?
Silly - if you added a fuse, is it functional?
My guess is you tripped up a ground connection
Do you have voltage on plates?
Silly - if you added a fuse, is it functional?
My guess is you tripped up a ground connection
Success! 😀
I feel like such a fool - the fuse had blown and naturally I'd forgot to check it. 🙄
Thankyou john65b for mentioning it. I feel incredibly relieved that I haven't turned this sweet little amp into a smoldering pile of metal as I feared.
As for the sonics, I will give it a few hours to warm up & settle in before doing some critical listening later tonight. But right now I'm just thrilled I was able to perform the mod successfully. Thanks again to OneyedK for your excellent instructions.
I feel like such a fool - the fuse had blown and naturally I'd forgot to check it. 🙄
Thankyou john65b for mentioning it. I feel incredibly relieved that I haven't turned this sweet little amp into a smoldering pile of metal as I feared.
As for the sonics, I will give it a few hours to warm up & settle in before doing some critical listening later tonight. But right now I'm just thrilled I was able to perform the mod successfully. Thanks again to OneyedK for your excellent instructions.
It's alive! Glad to hear it was an easy fix. I'm learning from my first DIY experiences that its really pretty difficult to TOTALLY wreck something but it can be super difficult to find the stupid little things.
Looking forward to hearing your impressions. Also, did you end up doing the diode mod you were talking about?
Looking forward to hearing your impressions. Also, did you end up doing the diode mod you were talking about?
Cheers bigjppop. Yeah, I think that's a pretty good summary of DIY. It can be pretty frustrating at times but the results are always worth it - and so much more satisfying that you've done it yourself.
I replaced the bridge rectifier with discrete diodes awhile back if that's the mod you referring to. I didn't notice much difference at the time, but this was before I'd performed any of the other mods. I may well try swapping those ultrafast diodes out for some shottky-types down the track but its low on my list of priorities.
Regarding the Triode mod, I've been listening constantly for the past few hours and can post some impressions.
The sound is now far more airy and spacious than before, possibly a tad more laid back too. Imaging has improved, as has bass impact to my surprise. Overall the soundstage is noticably better realized and seems more three dimensional. Music just seems to have more "atmosphere" than it did before. It's much easier to get actively involved in the listening experience, rather than feeling like a distant spectator.
It's very difficult putting the difference into words, but overall I'm pleased with the change and would not want to go back if I could. I can't even notice any drop in power so really there's no downside to performing the mod as far as I can tell, only the work I had to put in to perform it.
Speaking of the work, it was trickier than I originally imagined as de-soldering all the various wires so that the board can be removed from the case is pretty much a necessity.
Well worth the trouble in the end though!
This little amp now has a very 'high-end' sound that's plainly evident. With upgraded tubes I'm expecting it to get even better.
I'm wondering why global negative feedback is left in place after the triode mod. Surely it could be better without it? OneyedK might have an answer?
Ian.
Ian.
I didn't remove it (yet) for two reasons:
1) change one thing at a time, not two, otherwise you don't know what you are hearing after the change
2) I don't like fiddling with feedback without measurements to back it up, and I do believe this amp needs feedback
This being said, there is no reason not to try to remove the feedback wires and listen to the result. I'd suggest to remove them completely. (to make sure they don't start acting like an antenna)
My next steps will be changing the driver tubes, coupling capacitors (maybe also decoupling capacitors), re-bias the driver tubes, taking measurements with removed feedback. Choosing feedback values based on those measuremments.
But still waiting for the tubes and no time to do the measurements 😱
1) change one thing at a time, not two, otherwise you don't know what you are hearing after the change
2) I don't like fiddling with feedback without measurements to back it up, and I do believe this amp needs feedback
This being said, there is no reason not to try to remove the feedback wires and listen to the result. I'd suggest to remove them completely. (to make sure they don't start acting like an antenna)
My next steps will be changing the driver tubes, coupling capacitors (maybe also decoupling capacitors), re-bias the driver tubes, taking measurements with removed feedback. Choosing feedback values based on those measuremments.
But still waiting for the tubes and no time to do the measurements 😱
ohhh,
congratuation, Bosk. We might consider to offer triode mod on EL84. We did that before. but we thought the listening is not so good .so go back to penode mode. We will review this carefully again.
The DIYers do more than I can expect.
Oneydk, I am waiting to see the result you remove the feeback. Since at the time we develope this AMP, the dual fee back looks perfect. Oh, you just want to completely remove them! Yes, lets see what will happen.
That is really exciting to see how we can change it AMP.
The schematic of EL34 is ready. just post here and one copy on Bigjppop's post:
http://www.diyaudio.com/forums/tubes-valves/160924-new-suppo-audio-el34-amp.html#post2081103
Joed
congratuation, Bosk. We might consider to offer triode mod on EL84. We did that before. but we thought the listening is not so good .so go back to penode mode. We will review this carefully again.
The DIYers do more than I can expect.
Oneydk, I am waiting to see the result you remove the feeback. Since at the time we develope this AMP, the dual fee back looks perfect. Oh, you just want to completely remove them! Yes, lets see what will happen.
That is really exciting to see how we can change it AMP.
The schematic of EL34 is ready. just post here and one copy on Bigjppop's post:
http://www.diyaudio.com/forums/tubes-valves/160924-new-suppo-audio-el34-amp.html#post2081103
Joed
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Bigjppop- just wondering if your Tubelab SE is ready? Would be interesting to hear what do you think about sound of SSE versus Suppo...
I made my SSE using quality details, 5kg each Edcor OPT's, KT66 (needs small modification), speakers are 1 driver horn type of DIY and the result is IMHO excellent. Earlier you wrote, that you are planning to build Tubelab PP amp, is it because you need more volume out of amp?
Please let me know if you have got SSE to work, and what do you think about the sound.
I made my SSE using quality details, 5kg each Edcor OPT's, KT66 (needs small modification), speakers are 1 driver horn type of DIY and the result is IMHO excellent. Earlier you wrote, that you are planning to build Tubelab PP amp, is it because you need more volume out of amp?
Please let me know if you have got SSE to work, and what do you think about the sound.
spaudio
Hi, Joe. You don't answer my email. Is it EL84 still available in old "open" formfactor?
Hi, Joe. You don't answer my email. Is it EL84 still available in old "open" formfactor?
I got my Simple SE installed in its chassis and had a few bugs to work out; I'm close, but I've still got one more issue (sound only in one channel). Once I get that nailed down I'll try and do some comparing between the Simple SE and the Suppo. I've also got the new EL34 amp on the way so I should have plenty of options to try.
I've started building a chassis for the Suppo (solid Bubinga) and I'll be re-casing it soon (and I'm sure I'll do a little tweaking/modding along the way).
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When you evaluated triode mode, maybe the bias was too high... (would explain the loss of power)
I'm affraid you have to wait for measurements till the beginning of March, swamped with work at the moment 🙁
Hey guys, I ordered a GV-1 on 2/3/2010. How long did it take you to receive yours? I've not received any communication from Suppo since I placed the order. Was this the same for you?
Thanks. I look forward to receiving it. It should be fun to play with.
Bill
Thanks. I look forward to receiving it. It should be fun to play with.
Bill
it is this: since about one week most factories are closed here in china for the national holiday, spring festival. most of the people went home to their families somewhere in china. during the next 1..2 weeks also postal and other services are limited due to this.
Hi MashBill
My GV-1 arrived yesterday (Feb 11) it took nine full days to get to the UK as I ordered it very late on the 1st. I received an e-mail confirmation of the order on the 2nd saying it would be shipped next day.
On the 4th I received another e-mail confirming shipment with EMS Courier and my tracking number.
I was able to track it as it went through customs etc and it was easy to work out the day it would arrive.
I have been very impressed with Suppo Audio service so far.
My only gripes are:
1) No instruction manual, OK you don't need to know much but the tubes arrive with numbers on but no diagram to indicate which is socket number 1 etc. Also the 4 Ohm & 8 Ohm terminals are not labelled again a diagram would help.
Note: I found the info on the Suppo web site at:
http://www.suppomodel.com/audio/pic/rare.jpg
and
http://www.suppomodel.com/audio/pic/tubes Number.jpg
2) My amp does not apear to have the updated DP Switch & fuse etc. However I have not taken the covers off to confirm yet.
Sound wise it is fantastic. Much improved stereo image over my old transistor Amp. I am hearing instruments I have not noticed before in my old favourite songs, and you can pinpoint their location on the sound stage. I just wish it had a bit more power. More attack on the drums etc. Overall a fantastic improvement on my previous Amp.
Best Regards
Peter
My GV-1 arrived yesterday (Feb 11) it took nine full days to get to the UK as I ordered it very late on the 1st. I received an e-mail confirmation of the order on the 2nd saying it would be shipped next day.
On the 4th I received another e-mail confirming shipment with EMS Courier and my tracking number.
I was able to track it as it went through customs etc and it was easy to work out the day it would arrive.
I have been very impressed with Suppo Audio service so far.
My only gripes are:
1) No instruction manual, OK you don't need to know much but the tubes arrive with numbers on but no diagram to indicate which is socket number 1 etc. Also the 4 Ohm & 8 Ohm terminals are not labelled again a diagram would help.
Note: I found the info on the Suppo web site at:
http://www.suppomodel.com/audio/pic/rare.jpg
and
http://www.suppomodel.com/audio/pic/tubes Number.jpg
2) My amp does not apear to have the updated DP Switch & fuse etc. However I have not taken the covers off to confirm yet.
Sound wise it is fantastic. Much improved stereo image over my old transistor Amp. I am hearing instruments I have not noticed before in my old favourite songs, and you can pinpoint their location on the sound stage. I just wish it had a bit more power. More attack on the drums etc. Overall a fantastic improvement on my previous Amp.
Best Regards
Peter
Hi Guys
Sorry the links in my previous mail do not apear to work so here are the pics:
Tube Numbers:
4/8 Ohms:
Best Regards
Peter
Sorry the links in my previous mail do not apear to work so here are the pics:
Tube Numbers:
4/8 Ohms:
Best Regards
Peter
I received my GV-1 today. It was packed pretty well and the box appeared to be in good shape. Upon opening the box, I noticed several screws were loose. Suppo should consider using some kind of lock washer for the fasteners. The board looks high quality. I would rate the chassis a 6 out of 10. It's functional, but the fit and finish could be improved. Still, for what I paid I am pleased. I look forward to playing more with it tomorrow.
Hey, I received my amp (GV-2) about a week ago and it worked perfectly up until yesterday. Now the channels aren't equal anymore (about 60-70% difference in volume). The left channel is a lot quieter than the right channel. If I complete turn down the volume, the right channel is still quite loud and the left channel is completely silent.
I've switched the input signals but the left one remains the silent one. When switching output signals, the problem changed to the right speaker. I didn't change any tubes (because I don't have any, I could only flip the ones I have).
Does anyone have an idea what the source of the problem could be? My best guess would be the potentiometer although that's just a guess.😕
Thanks in advance for any answer.
I've switched the input signals but the left one remains the silent one. When switching output signals, the problem changed to the right speaker. I didn't change any tubes (because I don't have any, I could only flip the ones I have).
Does anyone have an idea what the source of the problem could be? My best guess would be the potentiometer although that's just a guess.😕
Thanks in advance for any answer.
It probably is the volume pot like the cheap stock one that was on mine. Try switching the 6N1 driver tubes and listen for any change in imbalance. Next, switch the right and left channel pairs of 6P15 power tubes. If the same imbalance exists, get a new 50K audio taper volume pot or stepped attenuator. This is the SMD stepped attenuator from eBay that I installed in mine. It's been fine since.
DACT Type 21 Stepped Attenuator Potentiometer 50K 300B - eBay (item 120473999989 end time Feb-23-10 10:05:02 PST)
Another possible source of the imbalance could be a difference between output transformers, but simply replacing the cheap volume pot has usually cured this problem.
DACT Type 21 Stepped Attenuator Potentiometer 50K 300B - eBay (item 120473999989 end time Feb-23-10 10:05:02 PST)
Another possible source of the imbalance could be a difference between output transformers, but simply replacing the cheap volume pot has usually cured this problem.
I had the amp disassembled (taking a look at the pot, turning it from left to right a few times to look what's wrong) and then re-assembled it to switch the tubes like you said, but it worked again without switching anything, so I assume it was just some dust built up in the pot😉
I think I still should switch the pot when I have some free time, so thanks for your advice!
I think I still should switch the pot when I have some free time, so thanks for your advice!
My JJ El84's arrived today so I swapped them in, going from the stock Chinese 6P15's.
Early impressions- Smoother tone, a bit less mechanical sounding and a slight increase in detail.
A worthwhile upgrade, though a bit expensive compared with the improvements yielded by the mods I've done.
Early impressions- Smoother tone, a bit less mechanical sounding and a slight increase in detail.
A worthwhile upgrade, though a bit expensive compared with the improvements yielded by the mods I've done.
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