No way. You will NOT get 20W at 2% distortion from a 300B SET. Not even close. 8 watts is considered the maximum output power without perceptable distortion. 20 watts would sound utterly horrible if you could even get that and the distortion would be in the double digits. I'm certain about that.
This claim (in my mind) completely discredits the amp manufacturer. I'm suspecting the amp is simply a piece of junk and the poor sound quality was there to begin with.
my apologies if there's a rule against asking the same thing on two different websites. the amp sounded exceptional at the dealers- comparing against other models and makes. i had the oscillation happen before i could hook it up to my speakers for the first time. on most websites the spec reads as 9Wx2 which i know is a more proper rating for a SET. never the less, i'll be sending in the amp back to the company next week and scan out the schematic and the gut photos should the amp come back unfixed. thanks for your help so far, gents. i wasn't trying to flame or magnet or whatever...
That's probably your best bet if it won't cost an arm and a leg and it's under warranty. You could also take it back to the dealers and compare it with the same amp or the amps that it sounded better than to see if yours still does or doesn't.
I post the same question sometimes on different forums. I often get different answers and ideas I wouldn't get confining myself to only one forum. That's cool.
just swapped out the rectifier with the SED 5U4G that i got in the mail today. i definitely notice more detailed and crispier sound. now i'm thinking if the muddiness could be due to tired tubes after all. the amp was suppose to have been a demo unit for 1.5 years at the dealer's but it's a discontinued model that was first released in 2004 so who knows.
on a second note, i'm now sad to know that switching from the SET to my yamaha receiver sounds like a major upgrade in transparency. Spark 743D is still veiled like a saudi woman.it's interesting how quickly our ear can change it's perception on fidelity. perhaps i wanted to like the SET amp too much. realizing the still dramatic shortcomings of my SET amp, now i'm thinking that the problem is more than just tired tubes. haha. to be continued in the far future when the amp gets shipped out to the factory. cheers.
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PreSapian,
How long have you had this amp?
We all want you to get it working, however if you ship it to the factory the cost may be a problem! Ask the cost of the repair from the factory. If all else fails use it as a project and replace the Output Tx's and rebuild.
I think the main problem is you don't know if you have a fault!
You ask us for opinions and don't seem to know what to do next. Please be proactive and actually try something even if you ask the dealer to let you try your ace amp on the speakers they demonstrated to you. Don't tell them the story! See if the amp compares with other models!
There is no problem asking the question on other forums. The problem is you are getting the same answers and get no closer to a solution! Decide on a plan of action, cheapest option first!
Regards
M. Gregg
How long have you had this amp?
We all want you to get it working, however if you ship it to the factory the cost may be a problem! Ask the cost of the repair from the factory. If all else fails use it as a project and replace the Output Tx's and rebuild.
I think the main problem is you don't know if you have a fault!
You ask us for opinions and don't seem to know what to do next. Please be proactive and actually try something even if you ask the dealer to let you try your ace amp on the speakers they demonstrated to you. Don't tell them the story! See if the amp compares with other models!
There is no problem asking the question on other forums. The problem is you are getting the same answers and get no closer to a solution! Decide on a plan of action, cheapest option first!
Regards
M. Gregg
Member
Joined 2009
Paid Member
This thread could be useful to those that follow even if poor PreSapien doesn't get what he needs from it to fix his amp.
And so onto precautions. I read somewhere else on this forum of a recommendation to put back emf Schotky diodes across the tube - apparently it's done on some commercial amps. It wasn't an attempt to damp out oscillations (Zobel is the solution I'd use there) but to prevent high reverse voltages across the tube.
Your thoughts seem to say otherwise though ?
A back EMF diode will at the very least damp any oscillations and help prevent the voltages getting too big. The best thing is to stop oscillation in the first place, with stoppers etc. A valve amp with no output or input ought to be safe, but it seems that some are not. Input signal but no output load is asking for trouble.
It would have been helpful if the OP had made it clear that he never heard the amp before the incident we have been trying to investigate. The poor sound he reports now may or may not be normal for this amp, depending on what he is comparing it against. The amp does seem to have good reviews, but if we all believed reviews we would not be building our own amps! I (like others?) assumed he was comparing 'before' and 'after'.
There is no rule about asking a question on several sites. However (and maybe I am old-fashioned) it seems to me that it is good manners to say so. Then we can decide whether we will offer free consultancy or leave someone else to do it. Incidentally, when I have noticed a question on here being repeated elsewhere the replies here tend to be more helpful, more detailed and less likely to merely repeat fashionable mantras. This is a place for good advice, but it helps if you tell us the whole story.
I hope the OP reaches a satisfactory conclusion. It may be that the amp is faulty, or it may be that his ears are not tuned to the strengths and weaknesses of SET.
It would have been helpful if the OP had made it clear that he never heard the amp before the incident we have been trying to investigate. The poor sound he reports now may or may not be normal for this amp, depending on what he is comparing it against. The amp does seem to have good reviews, but if we all believed reviews we would not be building our own amps! I (like others?) assumed he was comparing 'before' and 'after'.
There is no rule about asking a question on several sites. However (and maybe I am old-fashioned) it seems to me that it is good manners to say so. Then we can decide whether we will offer free consultancy or leave someone else to do it. Incidentally, when I have noticed a question on here being repeated elsewhere the replies here tend to be more helpful, more detailed and less likely to merely repeat fashionable mantras. This is a place for good advice, but it helps if you tell us the whole story.
I hope the OP reaches a satisfactory conclusion. It may be that the amp is faulty, or it may be that his ears are not tuned to the strengths and weaknesses of SET.
sorry, i think i did mention that the amp sounded exceptional at the dealers where i was able to compare against other models on speakers of same sensitivity as mine and of lesser fidelity. but sadly, the accident happened before i was able to hook it up to my speakers- hence the confusion of 'could it or could it not be?'
but lucky for me, i'm in china where the shipping is most cheap. it should only cost me little over $10 shipping it to the factory for a checkup. i don't believe i'll be lied to or be charged ridiculous price so there's my first line of solution. having used a 13Wx2 el84 amp in the past, i was expecting a greater degree of similar pros and cons but never expected the transparency to suffer.
on a side development,i was able to borrow my dad's pair of Amperex 6922 which has improved the instrument separation significantly. so now my wondering mind is once again thinking that it could be the tubes after all.
also i have noticed last night that the 300b with the lesser blue glow also sparks on the bottom plate when powering down.
p.s. anybody else think that their amperex 6922 sound bright? coming from sovteks, it certainly seem so. i'm getting used to all the wrong things, it seems.
but lucky for me, i'm in china where the shipping is most cheap. it should only cost me little over $10 shipping it to the factory for a checkup. i don't believe i'll be lied to or be charged ridiculous price so there's my first line of solution. having used a 13Wx2 el84 amp in the past, i was expecting a greater degree of similar pros and cons but never expected the transparency to suffer.
on a side development,i was able to borrow my dad's pair of Amperex 6922 which has improved the instrument separation significantly. so now my wondering mind is once again thinking that it could be the tubes after all.
also i have noticed last night that the 300b with the lesser blue glow also sparks on the bottom plate when powering down.
p.s. anybody else think that their amperex 6922 sound bright? coming from sovteks, it certainly seem so. i'm getting used to all the wrong things, it seems.
Interesting comparison with the Yamaha. A good SET might lose to the Yamaha in the bass department depending on the speakers but when it comes to midrange detail the SET should shine. Just more evidence indicating a problem. If that unit was a demo unit for a year and a half then any number of bad things could have occurred. I wonder if there is even a valid warrantee at this point.
As others have suggested, if you don't get satisfaction from the dealer or manufacturer then I would have at repairing/modding/redesigning it. If it comes to that I would look at OPT quality and circuit design.
Best of luck and please keep us posted as to how things progress.
As others have suggested, if you don't get satisfaction from the dealer or manufacturer then I would have at repairing/modding/redesigning it. If it comes to that I would look at OPT quality and circuit design.
Best of luck and please keep us posted as to how things progress.
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