I am building a amplifier:
Unity gain 15W class A symetrical triple emitter follower output stage.
For voltage gain my first thoughts were a tube circuit, but now I have thought at the possiblity for at mos-fet og j-fet driver/gain stage.
This would be something like a zen with output buffer and according to Nelson Pass' definitions a single stage amplifier 🙂
Is a bride of zen able of a +/-15-20V voltage sving without too much distorsion? Or should I look for at scaled down zen? Perhaps the new zen-9?
EDIT: There will be ac-coupling between driver and buffer stage and no NFB!
Unity gain 15W class A symetrical triple emitter follower output stage.
For voltage gain my first thoughts were a tube circuit, but now I have thought at the possiblity for at mos-fet og j-fet driver/gain stage.
This would be something like a zen with output buffer and according to Nelson Pass' definitions a single stage amplifier 🙂
Is a bride of zen able of a +/-15-20V voltage sving without too much distorsion? Or should I look for at scaled down zen? Perhaps the new zen-9?
EDIT: There will be ac-coupling between driver and buffer stage and no NFB!
From Some years i have realized a single stage power amplifier that can deliver 50 watt/8 ohm or more. This stage have voltage gain so allows to drive it with with a cd player also (however low impedance is necessary). It acceipt balanced and unbalanced inputs and can switch from single ended to push-pull operation.
Also it permit class A or A/B operation of course. No capacitors in signal wire, no FB. I have tried to buy SIT transistors (especially the Tokin TKS45F323/322/320, TKS15R52, TKS17R52, 2SK180 for the best performance, but as we know it is very difficult. Now, thanks this forum i am in listing to buy the Lovoltech JFet and then to try with its. (my scheme is patent pending). I search a collaboration to engineering this product also for commercial use.
There is one?
Francesco
Also it permit class A or A/B operation of course. No capacitors in signal wire, no FB. I have tried to buy SIT transistors (especially the Tokin TKS45F323/322/320, TKS15R52, TKS17R52, 2SK180 for the best performance, but as we know it is very difficult. Now, thanks this forum i am in listing to buy the Lovoltech JFet and then to try with its. (my scheme is patent pending). I search a collaboration to engineering this product also for commercial use.
There is one?
Francesco
single stage amplifier
Hi Mr. Pass.
At this time i have built 3 different power version of this amplifier:
8 W, 30 W, 50 W.
I have compared it with tubes amplifiers as:
leak TL 10 Point one (upgraded version)
Audio Tekne IT 2
DY-2 stages S-E amp (first stage 6463, output AD1 plus input (30k:50k) and interstage (30k:30k) transformes. Out tranny (all are made by Bartolucci) is 5k:16. First stage bias grid is obtained from battery. HV power from CLC filter and tube rectifier (Telefunken 1064 mesh). All filaments are in DC. Next days i will replace the 6463 with 6H30.
I also have compared my amp with solid states as:
Audio labor 8000
Classe Audio DR3 VHC (50 W class A)
Accuphase A50 V (50 W class A)
Spectral (i dont remember the model, perhaps DM 100)
Phatos Twin Tower
others.
I will canned evaluate the weak point of my amp and then improved it.
Now my last version sounds refined as near as the AD1 amp, tell me the friends, but it have other advantages such more dinamic, better bass etc
Do you think that i must insist on this project and offer a commercial version of this amp?
Can i make? (i dont have many money to spent)
Tell me an advice.
Best regards from Francesco.
Hi Mr. Pass.
At this time i have built 3 different power version of this amplifier:
8 W, 30 W, 50 W.
I have compared it with tubes amplifiers as:
leak TL 10 Point one (upgraded version)
Audio Tekne IT 2
DY-2 stages S-E amp (first stage 6463, output AD1 plus input (30k:50k) and interstage (30k:30k) transformes. Out tranny (all are made by Bartolucci) is 5k:16. First stage bias grid is obtained from battery. HV power from CLC filter and tube rectifier (Telefunken 1064 mesh). All filaments are in DC. Next days i will replace the 6463 with 6H30.
I also have compared my amp with solid states as:
Audio labor 8000
Classe Audio DR3 VHC (50 W class A)
Accuphase A50 V (50 W class A)
Spectral (i dont remember the model, perhaps DM 100)
Phatos Twin Tower
others.
I will canned evaluate the weak point of my amp and then improved it.
Now my last version sounds refined as near as the AD1 amp, tell me the friends, but it have other advantages such more dinamic, better bass etc
Do you think that i must insist on this project and offer a commercial version of this amp?
Can i make? (i dont have many money to spent)
Tell me an advice.
Best regards from Francesco.
Nelson Pass said:
some people don't even consider that a follower is an amplifying stage (voltage or current follower, so a cascode (folded or not) would be a 1 stage)
so, this amp would be a zero-stage amplifier 😀
some people don't even consider that a follower is an amplifying stage (voltage or current follower, so a cascode (folded or not) would be a 1 stage)
Many people consider the cascode a single stage (so the SRPP and the MU-follower) because the devices are in series and the current is the same.
However a triple followers must be consider as 3 stages.
Francesco.
Many people consider the cascode a single stage (so the SRPP and the MU-follower) because the devices are in series and the current is the same.
However a triple followers must be consider as 3 stages.
Francesco.
Like discussions about what constitutes feedback or Class A,
it is necessary to define what the terms mean, otherwise you
waste all your time on semantic arguments.
it is necessary to define what the terms mean, otherwise you
waste all your time on semantic arguments.
Looks to me as though this has already become a semantic discussion.
The entire point of calling a subgroup of parts by a particular name is to simplify analysis and discussion. It's nothing but a convenience for those who want to break a circuit down into smaller portions. The parts themselves surely don't care.
Grey
The entire point of calling a subgroup of parts by a particular name is to simplify analysis and discussion. It's nothing but a convenience for those who want to break a circuit down into smaller portions. The parts themselves surely don't care.
Grey
I would use LM4562 op. amp as a preamp (I have one preamp base on them).
They sound really great. Or LME49860, it's the same but can run with +-22V.
It has maximum output swing +-21V.
They sound really great. Or LME49860, it's the same but can run with +-22V.
It has maximum output swing +-21V.
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Thanks much Nelson.
This amp sounds with beautiful mids and highs. It is also very detailed, but not tire, a feast for the ears. The bass is extended but not particularly fast as most single ended circuits, then primarily it has a balanced sound. Since the amplifier is medium-low power (about 12-15 W), I hope someday to be able to match with medium-high efficiency speakers (Feastrex for example) and listen female voices. 😛
for me it would be interesting to know more about the differences in sound character by using of the good known IFFP 9240 or an other enhanced P-CH MOSFET. Are there really advantages in such a single ended power stage by use of this rare and expensive SONY V-FET instead enhanced MOSFET's?
Is this a commercial product from your country? I'm still looking to commercial single ended solid state power amps - an overview you will find about
2SJ109+2SK60
http://www.diyaudio.com/forums/soli...ended-integrated-power-amplifier-devices.html
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my english si very poor
Because no negative feedback loop circuit, using a different MOS tube out of the sound is different. In addition, this circuit is my own DIY, not manufacturers.