Dx hybrid amplifier will be produced soon

[destroyer X]

Excelent Pada..... then do it for us and publish here your results please.

and pictures.... and rofl.🙂

regards,

Carlos

 

[Bigun]

As requested - distortion profile from simulator. I likes it 🙂

 

[destroyer X]

Tubes arrived my adress dear Bigun

Thank you very much.

regards,

Carlos

 

[Bigun]

Wow, they took awhile but I'm glad they arrived safely. Remember, don't test the supply voltage with your tongue !

 

[destroyer X]

Tongue tester is painfull.

Maximum allowable test is with 9 volts batteries.

regards,

Carlos

 

[bra]

very good Jeff Macaulay's MOSCODE

 

[Junm]

any developments here?

 

[meanman1964]

Don't think so ,Carlos isn't active at this forum anymore

 

[Bigun]

It seems a pity to let this thread fade away - are there any veterans of Carlos' amplifiers that would like to take up the challenge of doing a hybrid worthy of DX approval ?

 

[destroyer X]

I gonna do it...i just do not know when

But for sure this gonna be made... one day.

Tubes are here...also your suggestions and schematics...all we need are here...it is a matter of time.

Thanks a lot dear Bigun.

regards,

Carlos

 

[Bigun]

But for sure this gonna be made... one day

🙂

 

[indra1]

It seems a pity to let this thread fade away - ...

Is there any progress? I have a proposal, how about this simple little circuit? I believe it still retains more than 70% DX original concept and use a low 100V for B+.

 

[Bigun]

This is a very nice suggestion !

DX- we're waiting...........

 

[gaborbela]

Is there any progress? I have a proposal, how about this simple little circuit? I believe it still retains more than 70% DX original concept and use a low 100V for B+.

Very clever.🙂
Gabor

 

[destroyer X]

Sorry to disappoint you folks....i am moved by curiosity

And now a days i am curious about digital amplifiers.

I hope curiosity to tubes comes next.

Also i do appreciate to create stuff myself... when you point me some schematic if loose a lot of energy.😱

It is alike to stay in a bar, or restaurant...and then you are open to flirt...then someone say...

- Can you see that girl over there?.... i do think she is nice...i do think she is pretty.... i do think i gonna be happy with here...so...you go to flirt with her😱.

My young age was plenty of tubes all around...TVs, audio equipment...all them had tubes. one of my first amplifier was tube... also Radio Frequency transmitters...the first stuff i have repaired was a tube control to elevators...not that curiosity to tubes now a days..but this is cyclic and i am sick for electronics...the passion may return one day.

My Class D is strange...and this drives me on.... sounds good and sounds bad at same time... bass you listen depending where you are.... it is powerful and it is weak... it looks too much strange... and waveform we can go shaping it...this is interesting to see the effects...have something that is driving my curiosity...for sure i do think Class AB is much better in sonics.... and that explains why this was around since the sixties (or before) and never really took off.

regards,

Carlos

 

[Junm]

Is there any progress? I have a proposal, how about this simple little circuit? I believe it still retains more than 70% DX original concept and use a low 100V for B+.

hi indra1

had you tested or build such amp...
I am very much interested with hybrids...

 

[Bigun]

Junm, Indra1 - you guys need to take charge of this thread and build it 😀

T4 might be replaced by a BJT (higher transconductance and not static sensitive)
Put a capacitor across R22, the quality of the voltage at the gate/base of T4 is very important, it needs to be as clean as possible as any noise here will be heard.

 

[still4given]

When I was a teenager I had an old console stereo that was tube. I used to love to crank up my Lee Michaels ambum and hear that Leslie speaker distort so fat!!!!!!!!!!!!

Boy, those were the days.

 

[destroyer X]

Yes Terry...those were the days

I am listening, right now:

Beach Boys - song talk about the 205 engine

https://www.youtube.com/watch?v=BcyGcmJTAdA

regards,

Carlos

 

[indra1]

. . . had you tested or build such amp...

Not as posted, I'm building a 6922 hybrid with latfet output. The circuit on post #52 is meant to preserve authentic DX output stage but needs tweaks for output offset adjustment and probably a DC servo. I actually hope that expert folks at TGM lab will proceed with the DX authorized hybrid development. It is very difficult to find a good FET for input nowadays. I think triodes are still plentiful enough as an alternative for a continuing development of good sounding amplifier.

. . . T4 might be replaced by a BJT (higher transconductance and not static sensitive)

Yes, as you already know, Rod Coleman successfully used 2N5401 and MPSA92 in the "Shunt Cascode Power Valve Driver" and the "does the 3A5 have the stones to drive a 2A3?" thread. But base current related distortion will tend to dominate total distortion as discussed in "My folded-cascode VAS linearity investigation" thread. One solution is to use high gain transistor, but another is to use FETs.

. . . Put a capacitor across R22, the quality of the voltage at the gate/base of T4 is very important, it needs to be as clean as possible as any noise here will be heard.

Yes, the quality of the psu is very important, a very clean HV supply is a definite must. However, if power is not clean enough, a cap across R22 will exacerbate hum problem because input of T4 is referenced to V+.

The attached circuit is what i am playing with, in no way finalized. I am still tweaking the PSU. Any comments, suggestions, and other alternatives are welcome. However, since the circuit is in no way resembles a DX Amp, this is OT. I hope Carlos does not take this as an offense.