Hello,
I am looking forward to build my second tube amplifier after assembling Scott's kit. I have never heard before a tube amplifier, never ever, so you can imagine the emotion I felt while assembling it. How will it sound after all the raving heard from tube fans? Before that, I have built several LM3886 based gainclones, a BPA-300 beast (6x LM3886 per channel), a Nelson's F5 class A, several discrete/opamps preamplifiers....
Now I understand it. It's not about measurements, or technology advances. It just sound VERY pleasing to my ears. As with having sex, you cannot measure pleasure. And you cannot neither compare opinions and likes to each others, and quantify it.
Those soooooooo sweet 5W per channel, KT88 class A in SE triode mode, are the best "food" I have tried. But I am still hungry, and I would like to have more of the same food but in a bigger dish. that means, more power.
I have been thinking in what would be my next project. Making amplifiers is based on making compromises, so more power will means less of other property.
But still, I would like to preserve all that is possible from the original SE amp. That means, I am thinking in building a KT88 based push-pull class A operating in triode mode. Being a big beast, it will be assembled on monoblocks, so I would like to put 4x or better 8x KT88 tubes per channel.
What would be a recommended design? Be aware that I am a tube noob, so I need a complete circuit and description. In the tube world I have seen that it is too much common for someone to post a design but leaving many factors up the the builder. Like saying something like "this is the driver section for this amplifier design, you just have to hook up the tubes and you're done". OK, but how to connect the tubes? What resistor values to use? Etc.
As an example, the said Nelson Pass F5 design is a pretty explanatory design. You don't need to understand at all how does it work (despite being advisable), you just get the schematic and assemble it as it is drawn. You want to tune it, or make modifications? OK. But if built as conceived, it will work at its best.
I would like the same, but for a tube amplifier with 8x KT88 in triode mode. I think I am done with solid state for a looooooooong time.
I have seen Peter's drivers board here. It may be possible for it to drive 4x/8x KT88, but it is an incomplete project as is. I am an idiot, there will be a moment that I may be able to easily conceive a tube design in minutes (like I am now able to do with opamps, for example), but for this moment to come I need some guidance.
Push-pull driver board
I just don't know how to hook up the tubes, set the bias, calculate resistor values, etc.
So I would like to ask you, is there any project out there that can fit my requirements (4x/8x KT88 Triode class A)?.
Best regards,
Regi
I am looking forward to build my second tube amplifier after assembling Scott's kit. I have never heard before a tube amplifier, never ever, so you can imagine the emotion I felt while assembling it. How will it sound after all the raving heard from tube fans? Before that, I have built several LM3886 based gainclones, a BPA-300 beast (6x LM3886 per channel), a Nelson's F5 class A, several discrete/opamps preamplifiers....
Now I understand it. It's not about measurements, or technology advances. It just sound VERY pleasing to my ears. As with having sex, you cannot measure pleasure. And you cannot neither compare opinions and likes to each others, and quantify it.
Those soooooooo sweet 5W per channel, KT88 class A in SE triode mode, are the best "food" I have tried. But I am still hungry, and I would like to have more of the same food but in a bigger dish. that means, more power.
I have been thinking in what would be my next project. Making amplifiers is based on making compromises, so more power will means less of other property.
But still, I would like to preserve all that is possible from the original SE amp. That means, I am thinking in building a KT88 based push-pull class A operating in triode mode. Being a big beast, it will be assembled on monoblocks, so I would like to put 4x or better 8x KT88 tubes per channel.
What would be a recommended design? Be aware that I am a tube noob, so I need a complete circuit and description. In the tube world I have seen that it is too much common for someone to post a design but leaving many factors up the the builder. Like saying something like "this is the driver section for this amplifier design, you just have to hook up the tubes and you're done". OK, but how to connect the tubes? What resistor values to use? Etc.
As an example, the said Nelson Pass F5 design is a pretty explanatory design. You don't need to understand at all how does it work (despite being advisable), you just get the schematic and assemble it as it is drawn. You want to tune it, or make modifications? OK. But if built as conceived, it will work at its best.
I would like the same, but for a tube amplifier with 8x KT88 in triode mode. I think I am done with solid state for a looooooooong time.
I have seen Peter's drivers board here. It may be possible for it to drive 4x/8x KT88, but it is an incomplete project as is. I am an idiot, there will be a moment that I may be able to easily conceive a tube design in minutes (like I am now able to do with opamps, for example), but for this moment to come I need some guidance.
Push-pull driver board
I just don't know how to hook up the tubes, set the bias, calculate resistor values, etc.
So I would like to ask you, is there any project out there that can fit my requirements (4x/8x KT88 Triode class A)?.
Best regards,
Regi
I forgot to add some more info. I will not be using tube rectifiers, this time I will go with solid state rectifiers. I am no longer afraid of using SS in depending what parts of the circuit. I have read enough arguments to convince me of their advantages versus tube rectification.
I have already ordered a pair of these boards, seems that lot of people like this kind of shunt regulators for preamp and gain stages:
http://www.diyaudio.com/forums/group-buys/206033-gb-salas-sshv2-regulator.html
So I have think in heatsinking the shunts in a Modushop enclosure with the heasinks on the sides.
I will use rectification and regulation for the filaments of the valves too, so if the enclosure has 1 heatsink per side, one of them can be used for the shunt PSU while the other one may go with a stack of, say, LM317 regulators.
I like this one for example, 3mm aluminium panels and available from 2U up to 5U rack size:
modushop.biz
Without the heatsinks, a Galaxy maggioratto seems like a good option too with 2mm top/bottom covers to mount so many tubes in a stable manner:
modushop.biz
For some money they will custom drill me the enclosures, something that will simplify the most (by far!) difficult part of the project:
modushop.biz
Front panel drilling, text engraving with ink filling...
They even provide top covers without slotting:
modushop.biz
Sorry for the OT! I may have gone far from the real issue of the topic.
I have already ordered a pair of these boards, seems that lot of people like this kind of shunt regulators for preamp and gain stages:
http://www.diyaudio.com/forums/group-buys/206033-gb-salas-sshv2-regulator.html
So I have think in heatsinking the shunts in a Modushop enclosure with the heasinks on the sides.
I will use rectification and regulation for the filaments of the valves too, so if the enclosure has 1 heatsink per side, one of them can be used for the shunt PSU while the other one may go with a stack of, say, LM317 regulators.
I like this one for example, 3mm aluminium panels and available from 2U up to 5U rack size:
modushop.biz
Without the heatsinks, a Galaxy maggioratto seems like a good option too with 2mm top/bottom covers to mount so many tubes in a stable manner:
modushop.biz
For some money they will custom drill me the enclosures, something that will simplify the most (by far!) difficult part of the project:
modushop.biz
Front panel drilling, text engraving with ink filling...
They even provide top covers without slotting:
modushop.biz
Sorry for the OT! I may have gone far from the real issue of the topic.
I forgot to add some more info. I will not be using tube rectifiers, this time I will go with solid state rectifiers. I am no longer afraid of using SS in depending what parts of the circuit. I have read enough arguments to convince me of their advantages versus tube rectification.
I have already ordered a pair of these boards, seems that lot of people like this kind of shunt regulators for preamp and gain stages:
http://www.diyaudio.com/forums/group-buys/206033-gb-salas-sshv2-regulator.html
So I have think in heatsinking the shunts in a Modushop enclosure with the heasinks on the sides.
I will use rectification and regulation for the filaments of the valves too, so if the enclosure has 1 heatsink per side, one of them can be used for the shunt PSU while the other one may go with a stack of, say, LM317 regulators.
I like this one for example, 3mm aluminium panels and available from 2U up to 5U rack size:
modushop.biz
Without the heatsinks, a Galaxy maggioratto seems like a good option too with 2mm top/bottom covers to mount so many tubes in a stable manner:
modushop.biz
For some money they will custom drill me the enclosures, something that will simplify the most (by far!) difficult part of the project:
modushop.biz
Front panel drilling, text engraving with ink filling...
They even provide top covers without slotting:
modushop.biz
Sorry for the OT! I may have gone far from the real issue of the topic.
I have already ordered a pair of these boards, seems that lot of people like this kind of shunt regulators for preamp and gain stages:
http://www.diyaudio.com/forums/group-buys/206033-gb-salas-sshv2-regulator.html
So I have think in heatsinking the shunts in a Modushop enclosure with the heasinks on the sides.
I will use rectification and regulation for the filaments of the valves too, so if the enclosure has 1 heatsink per side, one of them can be used for the shunt PSU while the other one may go with a stack of, say, LM317 regulators.
I like this one for example, 3mm aluminium panels and available from 2U up to 5U rack size:
modushop.biz
Without the heatsinks, a Galaxy maggioratto seems like a good option too with 2mm top/bottom covers to mount so many tubes in a stable manner:
modushop.biz
For some money they will custom drill me the enclosures, something that will simplify the most (by far!) difficult part of the project:
modushop.biz
Front panel drilling, text engraving with ink filling...
They even provide top covers without slotting:
modushop.biz
Sorry for the OT! I may have gone far from the real issue of the topic.
Also, PP is not a bigger dish of SE! If you like the SE dish, you have to get the same dish again, but bigger. As an example
the new EL34 Parallel Single Ended
This monoblock parallel 300b also looks good.
http://www.audionotekits.com/PDF/Manuals/MonoBlock300BParallel_NewChassisv2.pdf
Regards
http://www.audionotekits.com/PDF/Manuals/MonoBlock300BParallel_NewChassisv2.pdf
Regards
Because I play on 87db/W speakers (B&W CM-5). And to have the ability of producing concert-like levels if I carry it to a friend's place where we have A) Space and B) Big speakers. Open air, barbecue, beer... music is the fourth element of the equation
You are sure, 8x may seem a bit crazy. But there's no real reason for so much power, just want to do it because its uncommon. Doing it as big as we can, just because we can
I will go with 4x tubes per channel and 60W in triode, seems enough for my needed power.
Yeah, I know it is a very different beast (From what I've read. I haven't heard any PP yet), but I wanted to keep it as close as possible regarding:
-Triode mode
-Class A1 operation
-No feedback
-Conservative rating: Many tubes means same power, but long life for them.
I like your idea of more tubes in a SE setup, I didn't know it was possible to use more than 1 tube in SE to have more power. As it seems, I am a totally newbie in the tube world. Still much to read and learn, on the way
"there's no real reason for so much power, just want to do it because its uncommon"
It is uncommon because it is impractical, costly, and will be severely compromised in sound quality. If you really want to have a lot of power and great sound why not build a PP 845/211/GM70 amp. The first time you melt a meter probe on 1000V will give you a real thrill too.
It is uncommon because it is impractical, costly, and will be severely compromised in sound quality. If you really want to have a lot of power and great sound why not build a PP 845/211/GM70 amp. The first time you melt a meter probe on 1000V will give you a real thrill too.
I think the issue is he wants to do something 'different' that is not normally done, without realising that there is normally a good reason for it not being done. On top of that, he wants someone else to provide all the answers so he can have a unique amp.
Also, the design process is all *** backwards. 'I want 8 KT88 in triode and use these regulators I have already purchased, I want it to be unique and I want you to design it for me' is going to end in tears. Perhaps a statement of 'I like this KT88 SE amp I have, but I want to drive these 87dB speakers' is a better design starting point. Others will probably had a similar design goal and you will be able to look to their solutions for a suitable design.
In short - doing something different is great if you have the skills and resources to do it yourself. If you don't, and you want a solution presented on a platter - then look to a tried and tested design.
Cheers,
Chris
Also, the design process is all *** backwards. 'I want 8 KT88 in triode and use these regulators I have already purchased, I want it to be unique and I want you to design it for me' is going to end in tears. Perhaps a statement of 'I like this KT88 SE amp I have, but I want to drive these 87dB speakers' is a better design starting point. Others will probably had a similar design goal and you will be able to look to their solutions for a suitable design.
In short - doing something different is great if you have the skills and resources to do it yourself. If you don't, and you want a solution presented on a platter - then look to a tried and tested design.
Cheers,
Chris
Yeah, I know it is a very different beast (From what I've read. I haven't heard any PP yet), but I wanted to keep it as close as possible regarding:
-Triode mode
-Class A1 operation
-No feedback
-Conservative rating: Many tubes means same power, but long life for them.
I like your idea of more tubes in a SE setup, I didn't know it was possible to use more than 1 tube in SE to have more power. As it seems, I am a totally newbie in the tube world. Still much to read and learn, on the way
Nope, not close enough. If you like SE, it has to be SE. How about 4XGU50 triode per side? (35 watts per channel more or less)
Then we should change "Doing" by "Trying"? Trying, just because we can.Yes, I don't think he's aware of the trouble ahead.
Can you? We'll see.
In fact, I though I was asking for someting quite common. 4x tubes per channel in triode mode? I am a tube noob, but, is this REALLY a so strange thing? I am not needed for 1k watts, but something in the 30W-80W ballpark. Something that can stand up against a plain gainclone powerwise, nothing more.
I may admit I thought it was a bit exaggerated to think of 8x tubes per channel, or even arrogant. Now I am sure. Excuse my ignorance.
In fact, I though that a 4 tubes amp operating in triode wasn't a so "unique" thing, that's why I was asking for proved and tried designs, in order to compare them and learn how do they work. Why do values change between similar end designs. Why and how are things done in each case.
As I said.... that's really what I was asking for. I know that my end build will be unique in the sense that this is DIY and no two designs are exatly the same. But having some directions on already proved designs can give me some ideas on how to combine them.
Every project I have ever started never ended as the idea it started to be, so these are just my thoughts, not a final fixed idea. If it were, I were not asking for advice.
Thanks yoaudio for your valuable opinion, that's what I was asking for. My last one project was in the kit form, this time I would like to source components by myself. But that's the point of desing I was looking for.
Tony, I really like your project. A separate PSU when going so big is an interesting approach. I would have gone with a closed enclosure. Coming from the SS world, one thing surprises me is the common tube builders approach of placing components outside the case. I can understand it's done for valves for heat reasons, but seems to me that its too far common to place other unnecesary (and dangerous!) components outside the enclosure. For example, in your desing, I would have gone with the PSU in a closed case. That way it seems less obscene, fragile, and the tube module can be piled on top of it. But that's just my side of view
Great and impressive design all in all!
Thank you very much guys for your advices. They help my feet to keep on the floor.
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