Very Simple Hybrid Ampifier

Marc
Schematic from post 333
pot R15=1k is for DC balance correction
pot R10=1k is for biasing the triode, for ECC88 it is approx 5mA total and for ECC82 it is 1,7mA total (make sure that the R1=R2=R19=4.7k for ECC88 and 22k for ECC82)

Regards

In 12AU7 you have R10=5k and R6= 2k2 (VSHA classic final) as for ECC88 you have R10=1k and R6=680.
I have check R1/R2/R19 all is fine.

Marc
 
Gabor
I really have no experience with HEC circuit at all. Bellow is OPS from well known amp with toshiba mosfets, the drivers (I have them in stock anyway) can be IMHO substituted with BJT ones + small change ind Vbe circuit. I think you can try them out in the OS new V2 uni-OPS.
I do not know if HEC will bring any sonic improvement, the ''sound'' comes from the input stage mostly. If I were You I would wait for the V2 slevmaster which can take the mosfet transistors. I have too little knowledge for aplication of HEC circuit.
The OPS can be made with simple circuit and with well designed board the performace should be superb.

HI
Thank you Peter
I do have the Toshiba mosfet version without the HEC correction. If you would take a look of that.
Also I have to let you know I just pick up a pair module to have a Etalon amplifier.
HPA-NXV500L Lateral MOSFET Amplifier Module – Holton Precision Audio

I still want to build your Hybrid amplifier!
With that module I can not use your 6DJ8 IPS module.
So I must build something to use these IPS.
Now not necessary to be mosfet because the modules I purchased.
If you would take a look my Toshiba circuit, these is without the HEC (may be some other people interested on that)
Also has Jason's (very similar) with Hitachi LatFet with 3 pair output device if someone interested.

Greetings gabor
 

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Gabe , I don't think the full slew Vbe is right for the NTC of LFET's. Vfet's
and BJT's - perfect.
You might want to search my thread for Jkeutmann's LATFET mini OPS. I'm
not sure because I never had one ??
PS - the new OPS is JUST Vfet/BJT , LFET is a different DGS for outputs + a
different Vbe setup.
OS
 
Gabe , I don't think the full slew Vbe is right for the NTC of LFET's. Vfet's
and BJT's - perfect.
You might want to search my thread for Jkeutmann's LATFET mini OPS. I'm
not sure because I never had one ??
PS - the new OPS is JUST Vfet/BJT , LFET is a different DGS for outputs + a
different Vbe setup.
OS

Hi
Are the Toshiba devices LATFET or Vfet or something between.
It is confusing😕 not just because the pin out. Many people say those Toshiba devices not real LATFETs.
Many people swap the IRFP with the Toshiba devices or vice versa.
Greetings
 
Hi
Are the Toshiba devices LATFET or Vfet or something between.
It is confusing😕 not just because the pin out. Many people say those Toshiba devices not real LATFETs.
Many people swap the IRFP with the Toshiba devices or vice versa.
Greetings

I just looked em' all up - some toshiba are GDS , hitachi /renesis are GSD.
I never really cared , as I can buy a big MT-200 BJT cheaper. careful !
If they are GDS , swap away ! 😎
PS - they are not Vfet's , "DTFET " ?? could be oddball ?
OS
 
I just looked em' all up - some toshiba are GDS , hitachi /renesis are GSD.
I never really cared , as I can buy a big MT-200 BJT cheaper. careful !
If they are GDS , swap away ! 😎
PS - they are not Vfet's , "DTFET " ?? could be oddball ?
OS

Thank you OS
They are not DMOS but exchangeable with DMOS. The original Cordell HEC type was designed with DMOS and someone with a lot of knowledge and experience (Edmond Stewart) advised I can swap the DMOS with the Toshiba device.
What I badly need to someone run some simulation with these power devices.
I do have your LatFet OPS with 3 pair power fet.
I can post the layout if someone interested!
Al do the Hitachi, Exicon and other LATFETs are great audio devices the Toshiba outperform those specially at bass area.
Thank you one more time
By the way even Peter replaced the HexFet with these Toshiba devices in another project and get a lot of improvement.
I think that is why He also would like to do something with these mosfets.
I know those are getting rare or hard to fund but I do have some at hand it would be good to use them.

Greetings 🙂
 
OK the amp is singing. Sounds very, very nice. I think I may have found the problem with the other ECC88 board but I will have to check tomorrow. While I was waiting on some parts I went ahead and ordered some more tubes. I bought a pair of E-H 6922 tubes and a pair of Sylvania 6DJ8. Both work equally well. Then I tried one of the 6N1P tubes and I have a big offset. So I checked and I have 3V on the cathodes with the 6N1P and only .9V with the 6922 and the 6DJ8. One of the boards has less output. I am going to need to research that and see If I can find out why.

More later.

Blessings, Terry
 

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For testing today I used the Slew mini OPS which has one pair of Renases Lfets. Testing at +-47V rails.

This latest ECC88 IPS worked first try on both boards. This is a great sounding amp. I hope to attach it to Peter's OPS tomorrow. I want to hear what he is hearing. 😀

Blessings, Terry
 
OK the amp is singing. Sounds very, very nice. I think I may have found the problem with the other ECC88 board but I will have to check tomorrow. While I was waiting on some parts I went ahead and ordered some more tubes. I bought a pair of E-H 6922 tubes and a pair of Sylvania 6DJ8. Both work equally well. Then I tried one of the 6N1P tubes and I have a big offset. So I checked and I have 3V on the cathodes with the 6N1P and only .9V with the 6922 and the 6DJ8. One of the boards has less output. I am going to need to research that and see If I can find out why.

More later.

Blessings, Terry

Hi Terry
I see U using Peters boards, can you ell me the correct size by mm. From the front view (frame).
Thank you
Cheers
 
For testing today I used the Slew mini OPS which has one pair of Renases Lfets. Testing at +-47V rails.

This latest ECC88 IPS worked first try on both boards. This is a great sounding amp. I hope to attach it to Peter's OPS tomorrow. I want to hear what he is hearing. 😀

Blessings, Terry

Hi Terry,

Very nice update. Can you post the Slew mini OPS schematic and pcb layout. Appreciate your input. TIA.

Regards,
Boyet
 
Hi Terry,

Very nice update. Can you post the Slew mini OPS schematic and pcb layout. Appreciate your input. TIA.

Regards,
Boyet

Hi Boyet,

I'm attaching a PDF and word doc with iron transfer images. If you need Photo etch images let me know.

One note, since this layout is for single side you will need to run a ground wire from the G2 to the center terminal or to star ground,

Blessings, Terry
 

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