I have a dream...I want to build a really good tube-power-amp, that can handle a "normal" load (89dB / 8 ohm speakers), and fill a large room with sound of "modern" music.
I have a lot of prejudgment for tube amplifiers, have had a few small cheap ones...and heard a lot of really expensive sh**.
And have made some conclusions...(not necessarily correct, please educate me...)
I think I need a push-pull amplifier, I think I need 40(minimum)-80+watt output power. I have a 200W mosfetamp, and I sometimes use it ;-)
I like KT88 tubes & El34, 6SN7, 6SL7 & 12AX7 (as I have a few of them).
But I have no experience in setting up such a beast.
And no "iron" knowledge.
BTW, I hate hum, so I guess DC heaters are better?
Is there a schematic that I can use for a start?
Arne K
I have a lot of prejudgment for tube amplifiers, have had a few small cheap ones...and heard a lot of really expensive sh**.
And have made some conclusions...(not necessarily correct, please educate me...)
I think I need a push-pull amplifier, I think I need 40(minimum)-80+watt output power. I have a 200W mosfetamp, and I sometimes use it ;-)
I like KT88 tubes & El34, 6SN7, 6SL7 & 12AX7 (as I have a few of them).
But I have no experience in setting up such a beast.
And no "iron" knowledge.
BTW, I hate hum, so I guess DC heaters are better?
Is there a schematic that I can use for a start?
Arne K
I had a Dynaco ST70 for my "rock" music and it was much better than the SET's I have now. It will give you tube sound with headroom for loud music.
There are lots of places to find schematic on line and even a couple of places that sell it as a kit!
Off subject I grew up in Chicago and I was an extra in the Blues Brothers movie. Great tag line.
There are lots of places to find schematic on line and even a couple of places that sell it as a kit!
Off subject I grew up in Chicago and I was an extra in the Blues Brothers movie. Great tag line.
I should probably have written: NOT the sound of tubes...
as I want/need a "camelon", a transparent, and not "typical" tube-sound amplifier. I cannot play Sophie Zelmani or Eva Cassidy every day ;-)
My music collection also contains AC/DC...
I have soon spent a week surfing, & printing...and reading the book from Morgan Jones...
So many choices...
I would like to do a decent amp the first time, not time to experiment. Or I would have bought a Rogue...or...
Ok, ac heating is good enough, one choice less. 999 to go...
Arne K
BTW, I have been looking for a Dynaco Something 70...but they are extremely rare here...and expensive (the ones I have seen) in U.S.
as I want/need a "camelon", a transparent, and not "typical" tube-sound amplifier. I cannot play Sophie Zelmani or Eva Cassidy every day ;-)
My music collection also contains AC/DC...
I have soon spent a week surfing, & printing...and reading the book from Morgan Jones...
So many choices...
I would like to do a decent amp the first time, not time to experiment. Or I would have bought a Rogue...or...
Ok, ac heating is good enough, one choice less. 999 to go...
Arne K
BTW, I have been looking for a Dynaco Something 70...but they are extremely rare here...and expensive (the ones I have seen) in U.S.
Hi there...
I have doing quite a lot of reading on this subject lately, as I have also been looking into the subject of fullrangers too.
The conclusion seems to be that the old Dynaco stuff is not worthwhile, if you can't get them cheaply. The current Ebay trend seems to end at ++400$ for a used ST70, and even more for the higher powered amps. The irons in particular is not worth the money, as 2500-3000 NOK will buy you much better irons for a EL34 / KT88 / 6550 PP type amp.
I have doing quite a lot of reading on this subject lately, as I have also been looking into the subject of fullrangers too.
The conclusion seems to be that the old Dynaco stuff is not worthwhile, if you can't get them cheaply. The current Ebay trend seems to end at ++400$ for a used ST70, and even more for the higher powered amps. The irons in particular is not worth the money, as 2500-3000 NOK will buy you much better irons for a EL34 / KT88 / 6550 PP type amp.
Thanks, but I want an all-tube amp. I have a couple of good mosfet-amps, and a AIKIDO pre...
I have been looking / searching for old usable amps to modify/upgrade, but found nothing worth buying.
And there are few kits in the high-power-range, without an even heftier pricetag...
For an amp to modify/rebuild: The far-east seems most interesting, as I have mentioned somewhere; at least you can get a shiny chassi for less than $ 200, and a handfull of parts...of very variable quality...
At least it is a start, when you find that your large parts-bin only have sub-200Volt parts...
Arne K
BTW...is "GLASSWARE TUBE MANUAL" useful?
I have been looking / searching for old usable amps to modify/upgrade, but found nothing worth buying.
And there are few kits in the high-power-range, without an even heftier pricetag...
For an amp to modify/rebuild: The far-east seems most interesting, as I have mentioned somewhere; at least you can get a shiny chassi for less than $ 200, and a handfull of parts...of very variable quality...
At least it is a start, when you find that your large parts-bin only have sub-200Volt parts...
Arne K
BTW...is "GLASSWARE TUBE MANUAL" useful?
The Amplimo OPTs are all toroidals, right??
The prices are not bad at all, but toroids are still disputed in among the "Bottleheads" ??
I've been using SS amps for a lifetime, but I too have been eyeing at valves for quite a number of years. I also have a lot of experience with kW+ valve based transmitters, so I'm not afraid of the HVs either
The prices are not bad at all, but toroids are still disputed in among the "Bottleheads" ??
I've been using SS amps for a lifetime, but I too have been eyeing at valves for quite a number of years. I also have a lot of experience with kW+ valve based transmitters, so I'm not afraid of the HVs either
Most of the PP solutions will be one or the other variation on the classical williamson circuit (e.g. the famous dynaco although there are better alternatives); take your pick from one of the many circuits online (be it kt66 / kt88 / el34...). Transformer phase splitter could be interesting if you can afford it and dig something original (andrea ciuffoli has an x-former phasesplitter circuit for kt88 triode-wired but it probably doesn't take a genius to design a good amp with that topology; where simpler is better)... Although I haven't heard the tube yet kt88 has the reputation of sounding the most non-tubish (high and low-end extension and balls, not so much emphasis on midrange). Or mount a few tubes on your multiwatt SS for decoration
Simon
Simon
AuroraB said:The Amplimo OPTs are all toroidals, right??
The prices are not bad at all, but toroids are still disputed in among the "Bottleheads" ??
I've been using SS amps for a lifetime, but I too have been eyeing at valves for quite a number of years. I also have a lot of experience with kW+ valve based transmitters, so I'm not afraid of the HVs either
About toroids see
http://www.normankoren.com/Audio/TENA.html#Toroid
or he can order custom quality trafos with 10% cathode feedback windings, EI or 2Ccore.
http://www.ae-europe.nl/uitgangstrafo_engels.htm
Cobra2 said:
What about this kit? Will be a proof build and its 2X90W
http://www.velleman.be/nl/en/product/view/?id=19149
They're heavy, man.
If you build a valve amplifier you need transformers. At the very least, a pair of output transformers and a mains transformer. If you're building it yourself, you'll want to do it properly, and probably add an HT choke. Feeding the heaters from a separate mains transformer is a good idea too. What this all adds up to is that you're going to buy a lot of heavy, delicate iron that's expensive to transport. You certainly don't want to buy it from abroad. Logically, you probably ought to be basing your design around Lundahl transformers.
If you build a valve amplifier you need transformers. At the very least, a pair of output transformers and a mains transformer. If you're building it yourself, you'll want to do it properly, and probably add an HT choke. Feeding the heaters from a separate mains transformer is a good idea too. What this all adds up to is that you're going to buy a lot of heavy, delicate iron that's expensive to transport. You certainly don't want to buy it from abroad. Logically, you probably ought to be basing your design around Lundahl transformers.
Lundahl is closest, and seem to have a broad selection.
And, seems to be "midrange" priced, serious enough to be good, and helpful with questions
I have not decided if I will make it into mono-blocks, I guess the PSU price will be doubled...
I was also thinking of regulated PSU, but it does not seem like anybody cares about regulated PSU in a power-amp?
Arne K
And, seems to be "midrange" priced, serious enough to be good, and helpful with questions
I have not decided if I will make it into mono-blocks, I guess the PSU price will be doubled...
I was also thinking of regulated PSU, but it does not seem like anybody cares about regulated PSU in a power-amp?
Arne K
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