Looking for a new diy project

[cgraf]

Hi
As we soon move to a new house, it is time for a new tube amplifier!

I am looking for a really nice sounding push pull design, using el84 or also kt 88 tubes (as I like them). Initially I wanted to do a Single ended KT88 project, but yesterday night a colleague who is an audio professional convinced me to build a push pull amp.
I do not need a lot of power, actually I have an 8W tube amp which works fine, but I would like something around 15-20W to drive some less efficient speakers.

What I am looking for is a working schematics for a really nice sounding amplifier (other call it "high end").

Can anybody help me ? (I looked a lot into SE designs lately but am kind of lost of finding "the" schematics for a nice push pull amp.

Best regards

Christoph

 

[Helmuth]

http://www.triodedick.com/monobill_deel_1.htm

kt88 pp transformerset AE.
Automatic Electric Europe

 

[Doz]

I built one of these, slightly lower HT,GZ34 rectifier, 6550's and a 6n1p driver with LED CCS. Works nicely.

 

[Helmuth]

measurements.
frequency response without feedback.

thd

 

[Helmuth]

AE does supply transformer-sets for triode dick designs.
http://www.ae-europe.nl/voedingstrafo_engels.htm
the kt88 set.

KT88 PP
4 x tube Electro Harmonix KT88
2 x output transformer
2 x choke 10H 200mA
1 x power supply
€ 436

 

[Helmuth]

Welter highend UL output transformer PP-el84=Welter Ü 284 25Hz-58kHz -3dB price 70euro.

Welter Audio Electronic************************************************************************ Seit 1975

Or low cost Welter U3= 40euro PP el84
Welter Audio Electronic************************************************************************ Seit 1975

 

[Doz]

With both the above schematics, it would be wise to add 470K or so from the grid of the input to earth...

 

[mastodon]

With both the above schematics, it would be wise to add 470K or so from the grid of the input to earth...

Really? The 'Bill' design relies on fixed negative bias, marked 'nrs' in the design.

 

[Helmuth]

Oeps mistake.

transformerset monobill. MonoBill
Electroharmonics kt88 and JJ ecc99.

Inclusief 4 x EH KT88 en 2 x JJ ECC99
€ 603,-

 

[Helmuth]

Mains transformer two channel PP. Welter N3/4 price 54 euro.

german qaulity great prices. Need to buy the covers separate.
Welter Audio Electronic************************************************************************ Seit 1975

Highend version

HE-NT-PSE84 price 70 euro

 

[Helmuth]

Top piece of welter is a SE 6c33 end stage available as kit with all components and schematic.
Kit two mono. SE 6c33 endstages all the parts 452euro!
Welter Audio Electronic                                                                         Seit 1975

 

[h00hbt]

I have 1 powertransformer and 2 output transformers left over from my latest project. If you are going to build the integrated Bill KT88 amp these will be perfect. They are Bartolucci and sound fantastic. I have recently built the amp.

Specs for power transformer:

Pri:
230V, 294,6W

Sek:
1x290V 0,5A
2x5V 2A
2x6,3V 4A
2x3,15V 2A
1x40V 0,1A

Output transformers are pri 4K sec 4,8,16 ohm

If you are interested shoot me an e-mail

Cheers

 

[Helmuth]

Look at Hien topic a nice EL84 PP design. Maybe he can send you a PCB of the design.
http://www.diyaudio.com/forums/tubes-valves/161738-ultra-low-cost-6p1p-push-pull-schematic-pcb-4.html

 

[h00hbt]

Hi
As we soon move to a new house, it is time for a new tube amplifier!

I am looking for a really nice sounding push pull design, using el84 or also kt 88 tubes (as I like them). Initially I wanted to do a Single ended KT88 project, but yesterday night a colleague who is an audio professional convinced me to build a push pull amp.
I do not need a lot of power, actually I have an 8W tube amp which works fine, but I would like something around 15-20W to drive some less efficient speakers.

What I am looking for is a working schematics for a really nice sounding amplifier (other call it "high end").

Can anybody help me ? (I looked a lot into SE designs lately but am kind of lost of finding "the" schematics for a nice push pull amp.

Best regards

Christoph

Do you want to build an integrated amp or mono block power amp?

Cheers

 

[cgraf]

Hi guys

Thanks a lot for the info so far. I am looking more into an integrated amp, no monoblock. i am not really fixed on the kt88, just like the design.

Best regards
Christoph

 

[Eli Duttman]

Christoph,

I get the feeling that an "El Cheapo Grande" would do nicely for your project. Power O/P is "15" WPC in triode and "30" WPC in UL. The EC schematic uploaded shows 6V6 family tubes. To get a "Grande" you use 7591 "finals" and a higher B+ voltage voltage. Small signal circuitry that works with "12" W. O/P tubes also works with 7591s. Fisher, Scott, etc. took full advantage of that fact. You can too.

 

[h00hbt]

Hi guys

Thanks a lot for the info so far. I am looking more into an integrated amp, no monoblock. i am not really fixed on the kt88, just like the design.

Best regards
Christoph

Ok cgraf. I would recomend building Triode Dick´s Bill UL KT88. I have just finished building one, se post above, and I would say it´s the best PP amp Ivé built. I did change the PS to tube rectified GZ34 instead of using bridge SS rectifier. I have schematics for the PS if you are interested. Also if you need power transformer and doubble C-core output transformers I could set you up with Bartolucci transformers. Shoot me a message.....

Cheers

 

[Helmuth]

Hi guys

Thanks a lot for the info so far. I am looking more into an integrated amp, no monoblock. i am not really fixed on the kt88, just like the design.

Best regards
Christoph

No problemo. Here is bill stereo version.

english pdf
http://members.home.nl/triode.dick/pdf_files_td/Bill_En.pdf

 

[Helmuth]

more nice kt88 pp-transformers.
http://www.experience-electronics.de/englisch/Datenbl%E4tter/DBEAP234.pdf

 

[Helmuth]

El84 project.
Electra-Print EL 84 PSA PP Amplifier