Are you going to build one amp for musical instrument use? If this is the case then do you need UL?
For this kind of power you should check the Pete Millet Red Board amp:
http://www.diyaudio.com/forums/tubes-valves/151206-posted-new-p-p-power-amp-design.html
Read through
For this kind of power you should check the Pete Millet Red Board amp:
http://www.diyaudio.com/forums/tubes-valves/151206-posted-new-p-p-power-amp-design.html
Read through
Hi All ...
First thanks for your response.
What I seek is a tube amp for Hi Fi audio as a class AB.
Whether I'll need 8 pieces KT 88 or 6 KT 120 is unimportant, Output transformer supports 280 watts RMS and is OK.
The power supply, I will do it my myself, so there is a free choice with respect to current and voltage.
I have a set of old JBL L220 that I must have kicked started
As a preamp, I have a NAD T 163 which I am not so happy. there has been quite a few errors on it and in the near future I hope to have it replaced, it would be nice if I could do something with tubes
But it is somewhat difficult, since I also love watching movies and want DD / DTS, but it is a different matter, right now it is two pieces of mono block which is important.
Thanks to everyone who comes with a comment.
Best Regards Allan
First thanks for your response.
What I seek is a tube amp for Hi Fi audio as a class AB.
Whether I'll need 8 pieces KT 88 or 6 KT 120 is unimportant, Output transformer supports 280 watts RMS and is OK.
The power supply, I will do it my myself, so there is a free choice with respect to current and voltage.
I have a set of old JBL L220 that I must have kicked started
As a preamp, I have a NAD T 163 which I am not so happy. there has been quite a few errors on it and in the near future I hope to have it replaced, it would be nice if I could do something with tubes
But it is somewhat difficult, since I also love watching movies and want DD / DTS, but it is a different matter, right now it is two pieces of mono block which is important.
Thanks to everyone who comes with a comment.
Best Regards Allan
Who's using KT120's ? (I'm not).
6X KT90 parallel p-p should see 300W... I'm currently using 575V+ with 4x KT90
@ 2K A-A which gives close 200W;..... 4x hard pressed KT88's give around 160W in same circuit and todays makes won't last long. The 575V+ is the lowest B+ for such output power and the issue becomes the power supply and keeping the weight down.
I took my 200+200W design with regards "wear and tear" using the lowest usable B+ quite seriously, designed with sufficient natural ventilation.
Having been disappointed by the high failure dropouts of the TungSol 6550 New Edit on a lower power variant,
My design emphasis has shifted to lowest B+ for a given power. Only my philosophy and approach.
richy
6X KT90 parallel p-p should see 300W... I'm currently using 575V+ with 4x KT90
@ 2K A-A which gives close 200W;..... 4x hard pressed KT88's give around 160W in same circuit and todays makes won't last long. The 575V+ is the lowest B+ for such output power and the issue becomes the power supply and keeping the weight down.
I took my 200+200W design with regards "wear and tear" using the lowest usable B+ quite seriously, designed with sufficient natural ventilation.
Having been disappointed by the high failure dropouts of the TungSol 6550 New Edit on a lower power variant,
My design emphasis has shifted to lowest B+ for a given power. Only my philosophy and approach.
richy
Hi All...
# SY
Non.... hoever I have built MosFet Power amp, 2 stereo amp 150W @ 8 Ohm and 1 stereo 250W @ 8 Ohm.
My education is Elektromekanic and electronics technician, the electronic part is the same as an electronics engineer, but it was 15 years ago.
# richwalters
It sounds exciting I am not fixated on anything special besides I wanted to use Hammond 1650W as it would be pretty expensive to get a big output transformer shipped to Denmark and beyond what should I pay 25% VAT. : (
I'd like to see a schematic of the amplifier that you've built, it sounds exciting.
PS: Thanks for your interest in my forthcoming AMP
# SY
Non.... hoever I have built MosFet Power amp, 2 stereo amp 150W @ 8 Ohm and 1 stereo 250W @ 8 Ohm.
My education is Elektromekanic and electronics technician, the electronic part is the same as an electronics engineer, but it was 15 years ago.
# richwalters
It sounds exciting
I am not fixated on anything special besides I wanted to use Hammond 1650W as it would be pretty expensive to get a big output transformer shipped to Denmark and beyond what should I pay 25% VAT. : (I'd like to see a schematic of the amplifier that you've built, it sounds exciting.
PS: Thanks for your interest in my forthcoming AMP
Hi All
# DF96
Thanks for the recommendation, but I'm going to continue with a tube amp at 250 to 300 W
I have previously repaired Hig Power Transformer 10 K Volt 60 Amp, of prima side. a big boy I have also repaired the electronics industry for 15 years where the last 5 years I have repaired servo drive at component level. so there for I intend to continue, although my knowledge of tubes is limited.
So I'm ready to try, and hope it goes well
if not then I take it from there
Best Regards Allan
# DF96
Thanks for the recommendation, but I'm going to continue with a tube amp at 250 to 300 W
I have previously repaired Hig Power Transformer 10 K Volt 60 Amp, of prima side. a big boy
I have also repaired the electronics industry for 15 years where the last 5 years I have repaired servo drive at component level. so there for I intend to continue, although my knowledge of tubes is limited.So I'm ready to try, and hope it goes well
if not then I take it from there
Best Regards Allan
Here is one well known example; 400 W with 10 KT88.
This can be quite easily modified for the power level you want.
The Wireless World Archive
Here is the book from GEC where the later version of the same contruction is described (from page 112...):
http://www.tubebooks.org/Books/GEC_approach.pdf
This can be quite easily modified for the power level you want.
The Wireless World Archive
Here is the book from GEC where the later version of the same contruction is described (from page 112...):
http://www.tubebooks.org/Books/GEC_approach.pdf
I think you can try Citation II mod developed by Stew Hegeman. He replaced KT88 with KT120, changed output taps, and got about 120W. You can try to install a quad of KT120 in order to get over 200W.
PS. I sent you a PM regarding repairing servo motors.
If you dont necessary need to see the glow then theres always this, from Bob Danielak. I know it is not a Ultralinear design but you cant beat the simplicity. Of course the B+ is a little high! 800 to 1000v will get you to where you need. The mirror site that had all the information about this amp is gone but I do have most of it saved. Cheers
Attachments
As mentioned before look at this thread:
http://www.diyaudio.com/forums/tubes-valves/151206-posted-new-p-p-power-amp-design.html
Yes it starts out as a mild mannered 18WPC amp. Read the whole thread or at least up to post #800 or so if you really want to find the simplest way to make a powerful tube amp. I have seen my board put out 525 watts wired as a single channel mono block. There are currently a few of us building amps at the 125 WPC level using one board. Use two boards, and wire each one as a 250 watt mono block.
Some fresh boards are getting assembled now so there will be a bunch more posts soon.
http://www.diyaudio.com/forums/tubes-valves/151206-posted-new-p-p-power-amp-design.html
Yes it starts out as a mild mannered 18WPC amp. Read the whole thread or at least up to post #800 or so if you really want to find the simplest way to make a powerful tube amp. I have seen my board put out 525 watts wired as a single channel mono block. There are currently a few of us building amps at the 125 WPC level using one board. Use two boards, and wire each one as a 250 watt mono block.
Some fresh boards are getting assembled now so there will be a bunch more posts soon.
I'd like to see a schematic of the amplifier that you've built, it sounds exciting.
PS: Thanks for your interest in my forthcoming AMP
I share your interest but designing amps at this power class, my approach living in a wooden house, the biggest fear is fire so there is alot of safety built in to avoid destruction of critical components and when things go wrong at this power level, they go fast. As my designs are Williamson based, the output transformers and circuit have been specifically designed to mate, and using a designed circuit with another vendor o/p tranny, the results can lead to problems and at the 200-200W level with wide bandwidth, the ratings and layout become important. The Citation is a classic example.
What makes you want to start with such a high power ? The GEC 400W is just a "normal" performer, I would rate it fine for MI, not HiFi.
SOWTER AUDIO TRANSFORMERS has this o/p tranny listed.
richy
http://www.diyaudio.com/forums/tubes-valves/183385-modifying-classic-williamson-5.html#post2485835
See post#43
I can get rid all but one cap in Williamson by throwing some P sand at the problem.
Fewer caps and more DC coupling might make transformer quality less critical?
Just a sim right now, but circuit looks do-able. A little AB2 action, and no blocking.
See post#43
I can get rid all but one cap in Williamson by throwing some P sand at the problem.
Fewer caps and more DC coupling might make transformer quality less critical?
Just a sim right now, but circuit looks do-able. A little AB2 action, and no blocking.
Last edited:
Hmm ... why ... Yes it's a good question, I will try to answer it.
I am a man aged 45 and married with two children aged 9 and 15 I've got the ability to tow get some audio equipment into my living room
And here it is. I do NOT want an amplifier of 25 W and especially not with the speaker I have
I work daglit with electronics and especially the Power Electronic. For example, In a servo drive output stage, there are DC voltages up to 840 VDC, the largest I've worked with were 346 AMP @ 600 to 840 VDC. So I know perfectly well what happen when things go wrong, and it does not look good when it blow up, here we are talking about metal grille in a thickness of 3mm which is burned away, just a big black hole
So I'm not so afraid of tension perspective, I know perfectly well consequence it has.
I'm in my early youth I reaperert TVs with tubes, but it's very long time ago. In audio linkage I have built 3 Amplifier with MOSFET transitor, with have a Power supplay 185 VDC 12Amp and capacitor 40000uF
I also have the metering equipment as needed to work with electronics.
Here are my "work shop"
vario transformer from 0 to 400 VAC 32 Amp
LeCroy 9450 Digital Oscilloscope: 350 MHz, 2 Ch., 400 MSa/s 10GS (9450) with IEEC output. and Hameg 60MHz
DC supplay 2 X 0 - 30VDC 2Amp
Rohde & Schwarz Programmable DC Power Supply NGSM32/10 with IEEC output.
Measuring instrument with a crest factor of 7
Phillips function generator 10mHz - 20MHz with IEEC output.
2. Hameg function generator 8000 serie
Now I do not want to sound like a Grumpy Old Man.
I also understand that you do not know me, and I'm quite new to this forum and therefore you are skeptical of my abilities, but as I said earlier, I'm no Wizard with tubes
but I know the basic about tubes. Do not be afraid I f *** up, and if this should happen, I will not get hurt, you can be absolutely sure of it.
I will not blame anyone, but myself if something goes wrong.
So just feel free to throw some drawings. I am not able to dimension tube amplifier, so it must be complete drawings.
I do not want to offend anybody in any way. I would just like to make me a 250 W 300 W tube amp before my wife have second thoughts
excuses
1. You all know, one should strike while the iron is hot !
2. One can always blame the wife, she can handle it !
3. I want to make the amp as long I have credit on my wife’s account ! ( how knows it may not last for long )
Anyway
And Last, Bot Not Least, Thanks To All Who Helps With My Tube Amp...
Here are a few photos of my little "work shop"
I am a man aged 45 and married with two children aged 9 and 15 I've got the ability to tow get some audio equipment into my living room
And here it is. I do NOT want an amplifier of 25 W and especially not with the speaker I have
I work daglit with electronics and especially the Power Electronic. For example, In a servo drive output stage, there are DC voltages up to 840 VDC, the largest I've worked with were 346 AMP @ 600 to 840 VDC. So I know perfectly well what happen when things go wrong, and it does not look good when it blow up, here we are talking about metal grille in a thickness of 3mm which is burned away, just a big black hole
So I'm not so afraid of tension perspective, I know perfectly well consequence it has.
I'm in my early youth I reaperert TVs with tubes, but it's very long time ago. In audio linkage I have built 3 Amplifier with MOSFET transitor, with have a Power supplay 185 VDC 12Amp and capacitor 40000uF
I also have the metering equipment as needed to work with electronics.
Here are my "work shop"
vario transformer from 0 to 400 VAC 32 Amp
LeCroy 9450 Digital Oscilloscope: 350 MHz, 2 Ch., 400 MSa/s 10GS (9450) with IEEC output. and Hameg 60MHz
DC supplay 2 X 0 - 30VDC 2Amp
Rohde & Schwarz Programmable DC Power Supply NGSM32/10 with IEEC output.
Measuring instrument with a crest factor of 7
Phillips function generator 10mHz - 20MHz with IEEC output.
2. Hameg function generator 8000 serie
Now I do not want to sound like a Grumpy Old Man.
I also understand that you do not know me, and I'm quite new to this forum and therefore you are skeptical of my abilities, but as I said earlier, I'm no Wizard with tubes
but I know the basic about tubes. Do not be afraid I f *** up, and if this should happen, I will not get hurt, you can be absolutely sure of it.
I will not blame anyone, but myself if something goes wrong.
So just feel free to throw some drawings. I am not able to dimension tube amplifier, so it must be complete drawings.
I do not want to offend anybody in any way. I would just like to make me a 250 W 300 W tube amp before my wife have second thoughts
excuses
1. You all know, one should strike while the iron is hot !
2. One can always blame the wife, she can handle it !
3. I want to make the amp as long I have credit on my wife’s account ! ( how knows it may not last for long )
Anyway And Last, Bot Not Least, Thanks To All Who Helps With My Tube Amp...
Here are a few photos of my little "work shop"
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
"I want to make the amp as long I have credit on my wife’s account" NICE! When the wife give you the green light you hit the gas!
If I were you... Buy some of the new Mono Block amps that Bob Latino is selling in kit form. his M125 mono blocks. These go 125 Watt / Chan. but you plug in 4 KT 120 and they go up more around 140.. 140 Watts a channel will rock large disco techs and get you in enough trouble with your wife. Kits are good for a 1st pass with tubes .
If I were you... Buy some of the new Mono Block amps that Bob Latino is selling in kit form. his M125 mono blocks. These go 125 Watt / Chan. but you plug in 4 KT 120 and they go up more around 140.. 140 Watts a channel will rock large disco techs and get you in enough trouble with your wife. Kits are good for a 1st pass with tubes .
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