Stereo Homecinema with Quasi
Hi Fellas,
first to all thanks for the good and kind working together (ideas, boards, help, advise, explanation)- a nice project to enjoy and learn a bit.
after several days listening with burn in the foil cap (same as in FetZilla) this amp plays very cool. 😀 😀
The PSU is only 28VDC- 2 x cap bank each 4 x 6800uF/40V + MUR820.
On Input is a 100k pot- and this animal has a lot gain- dynamic goes forward, if you turn pot more cw- wow.
It has an fresh breath. From mids to topend it is very clear and transparent-
nuances in micro details are easy listenable. So you mean losses in bass- no no- it plays deep and well contoured too- even slimm not thin!!!
Stage is on speaker line and with good material goes easy form speaker forward, backward and also wider out of speaker with more clear separation
as other builds- FX8 is a bit more closed together.
This amp is close in neighborhood with other who i like in tonality- every is a
bit different what is preferential.
And here comes the Fetzilla in to the game. 😛 half finished case now
It could be because i have add a PIO to the input foil cap this gives a other
coloration?
That is the point where wins the FZ to me. The female vocals, brass and strings have a bit its own color and bit more fuller bodied tonality- difficult to describe, but i like that more for long listening.
Could it have to do with LatFet there? on other hand the LAPT Sanken plays
fresh, not harsch- i know.
With Sanken 3263 i have build the W.d.Haan Nishiki Quasi Hybrid Amp, but
not fully wired now- pic. It has a 6N1P in srpp on input with ~320V Ub anode.
That one plays in same league for my opinion- have to finish wiring.
And than its time to create a new case for that Quasi animal. 🙂 and get a steady place.
Hi Fellas,
first to all thanks for the good and kind working together (ideas, boards, help, advise, explanation)- a nice project to enjoy and learn a bit.
after several days listening with burn in the foil cap (same as in FetZilla) this amp plays very cool. 😀 😀
The PSU is only 28VDC- 2 x cap bank each 4 x 6800uF/40V + MUR820.
On Input is a 100k pot- and this animal has a lot gain- dynamic goes forward, if you turn pot more cw- wow.
It has an fresh breath. From mids to topend it is very clear and transparent-
nuances in micro details are easy listenable. So you mean losses in bass- no no- it plays deep and well contoured too- even slimm not thin!!!
Stage is on speaker line and with good material goes easy form speaker forward, backward and also wider out of speaker with more clear separation
as other builds- FX8 is a bit more closed together.
This amp is close in neighborhood with other who i like in tonality- every is a
bit different what is preferential.
And here comes the Fetzilla in to the game. 😛 half finished case now
It could be because i have add a PIO to the input foil cap this gives a other
coloration?
That is the point where wins the FZ to me. The female vocals, brass and strings have a bit its own color and bit more fuller bodied tonality- difficult to describe, but i like that more for long listening.
Could it have to do with LatFet there? on other hand the LAPT Sanken plays
fresh, not harsch- i know.
With Sanken 3263 i have build the W.d.Haan Nishiki Quasi Hybrid Amp, but
not fully wired now- pic. It has a 6N1P in srpp on input with ~320V Ub anode.
That one plays in same league for my opinion- have to finish wiring.
And than its time to create a new case for that Quasi animal. 🙂 and get a steady place.
Attachments
Are you using the same input cap on the Fetzilla and Quasi ?
If not, can you run the Fetzilla and Quasi test using the same input cap ?
Edit:
I just noticed that you did say.. after several days listening with burn in the foil cap (same as in FetZilla) this amp plays very cool...."
Can you describe the 'difference' ( if any !) between the amplifiers 'with the same input cap' ?
Thanks.
If not, can you run the Fetzilla and Quasi test using the same input cap ?
Edit:
I just noticed that you did say.. after several days listening with burn in the foil cap (same as in FetZilla) this amp plays very cool...."
Can you describe the 'difference' ( if any !) between the amplifiers 'with the same input cap' ?
Thanks.
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Very nice builds BanglaH! I looked around and could not find any Gerbers for the Fetzilla. Are they only available as pre-made PCB's? Is there a link to where to get the PCB's?
One of my favorite input cap combos is a very small (and inexpensive) 10uF 50v MLCC to get the bass, bypassed with between a 100nF 100v to 1uF 250v film cap. Sounds just fine to my ears. The 100nF option os overall very compact and fits on the smallest of amps.
You'll not find any Gerbers of the FetZilla cause it's a layout design of Hugh Dean.I've a a fetzilla groupsbuy running which is on hold for now you can fill in your name here
https://docs.google.com/spreadsheets/d/1as6aMLORhhyUSyoCOOMlIPA_B781Jnn026FvGcz33Ps/edit#gid=0
and look here too
http://www.diyaudio.com/forums/group-buys/286085-fetzilla.html
same QXP on Input
Hi guys.
Thanks for kind reply.
Ashok the only different is the paralleled 10n cap- on Quasi is an old FKC-polycarbonate (ZM used 1uF- there is borrowed idea).
The FKC i have tested on Apex FX8 with 10uF electrolytic with surprisingly
very good clean sound- my indicator is clapping hands- very precise, same on
Quasi.
Today i have better ears and registered again a very good 3D imaging of
Quasi and fluide musicality- one song plays very delicious
The Fetzilla is there a bit different i would say- LatMos as OP, warm class AB
bias point and the refined PSU- CRC, what Ranchu has worked out with any
more members and well supported by Hugh. 😀
If there is more interess- MM has done a great offer to us- not many registered that- of course that one is a bit more expensive...... and so on...
I have add to QXP there the K40Y-9 PIO cap- same experiment done on Jasons VSSA (with long antennas cap legs- bad!!! 😕 😛 ) and a DME
10uF- works also great with any magic in sound- i like it.
I tough every one does it's own experience with caps and what he like. 😱
Another impressing thing is: if i switched off the Quasi it is slow discharging-
near a minute you can listen on speaker- like a tube amp- electrodes flowing.
Makes me little smile there- only nice. 🙂
Could it be because the VFet stays permanently ON?
Hi guys.
Thanks for kind reply.
Ashok the only different is the paralleled 10n cap- on Quasi is an old FKC-polycarbonate (ZM used 1uF- there is borrowed idea).
The FKC i have tested on Apex FX8 with 10uF electrolytic with surprisingly
very good clean sound- my indicator is clapping hands- very precise, same on
Quasi.
Today i have better ears and registered again a very good 3D imaging of
Quasi and fluide musicality- one song plays very delicious
The Fetzilla is there a bit different i would say- LatMos as OP, warm class AB
bias point and the refined PSU- CRC, what Ranchu has worked out with any
more members and well supported by Hugh. 😀
If there is more interess- MM has done a great offer to us- not many registered that- of course that one is a bit more expensive...... and so on...
I have add to QXP there the K40Y-9 PIO cap- same experiment done on Jasons VSSA (with long antennas cap legs- bad!!! 😕 😛 ) and a DME
10uF- works also great with any magic in sound- i like it.
I tough every one does it's own experience with caps and what he like. 😱
Another impressing thing is: if i switched off the Quasi it is slow discharging-
near a minute you can listen on speaker- like a tube amp- electrodes flowing.
Makes me little smile there- only nice. 🙂
Could it be because the VFet stays permanently ON?
Thank you Bangla, you are experienced with amp building and listening and I agree with just about everything you describe.......
If anyone wants to build a FetZilla, please talk with Meanman, he is DA MAN!!
Hugh
If anyone wants to build a FetZilla, please talk with Meanman, he is DA MAN!!
Hugh
Thanks Bangla. I wondered if the there were differences and of course there is usually something different. I found that Latfets in some of my amps were a bit lighter in the bass though there was no difference in the frequency response at LF.
I did find some surprisingly good performance with some electrolytic caps at the input. I was expecting some softening in the HF but it came through very well ! Not all brands of electrolytics were as good.
I have used a 10nF polyprop cap ( inexpensive dip type) across the input caps and in some cases they appeared to improve the clarity at HF.
Haven't been able to get my version of Quasi done. This will take a while I think !
I did find some surprisingly good performance with some electrolytic caps at the input. I was expecting some softening in the HF but it came through very well ! Not all brands of electrolytics were as good.
I have used a 10nF polyprop cap ( inexpensive dip type) across the input caps and in some cases they appeared to improve the clarity at HF.
Haven't been able to get my version of Quasi done. This will take a while I think !
the orange drop cap
thanks Hugh and Ashok for kind reply and reflecting.
Yes - experienced in building (not every project with success 🙁), and well
listening over the years- must be mindful don't lost good quality ears in older
days now! 😛 😀.
Ashok- if you could build the little FX8- you would be surprised how good a
LM without source resistors.
For comparing without in put cap i must set under current my shaan/olafk peeceebee.
Mr. Pass and 6L6 in Pass Forum using the Elna Silmic II very satisfied- that i will try next on ACA with my loved orange drop P-715/716 (size, price, performance)
Here on Quasi could be good to play with Clarity SA or different big PP- i feel
they have more dark background- more flattering ears. 🙄
Here comes again the Fetzilla in- 0,1R on source- high quality- robust stability.
Next time i have finitely to test the 100k option in PL position to compare
bass response- what would happen next!!- promised! 🙂
We keep too the FZ on life, hopefully.
And than stops it for me with deeper detailed knowledge- but i continuously
keep on learning more.
thanks Hugh and Ashok for kind reply and reflecting.
Yes - experienced in building (not every project with success 🙁), and well
listening over the years- must be mindful don't lost good quality ears in older
days now! 😛 😀.
Ashok- if you could build the little FX8- you would be surprised how good a
LM without source resistors.
For comparing without in put cap i must set under current my shaan/olafk peeceebee.
Mr. Pass and 6L6 in Pass Forum using the Elna Silmic II very satisfied- that i will try next on ACA with my loved orange drop P-715/716 (size, price, performance)
Here on Quasi could be good to play with Clarity SA or different big PP- i feel
they have more dark background- more flattering ears. 🙄
Here comes again the Fetzilla in- 0,1R on source- high quality- robust stability.
Next time i have finitely to test the 100k option in PL position to compare
bass response- what would happen next!!- promised! 🙂
We keep too the FZ on life, hopefully.
And than stops it for me with deeper detailed knowledge- but i continuously
keep on learning more.
Attachments
Bangla..that's a nice neat looking simple chassis !
I often just fit everything to a heat sink and then after testing it often goes into storage !🙂
The urge to keep trying different circuitry expecting something better will be possible , is like a virus without an "antidote" ! 😀 Can't get away from the affliction ! Very expensive pleasurable illness !🙂
I want to put a protection relay on my board along with the PSU caps. Or maybe I'll just use my external PSU cum protection board to save on time. To do a rough cut (!) I'll make one board using the laser printer method. That needs lots of rework but is faster than going to a board house.
I will use the following...( just because I have them !) 2SA992, 2SC1845, 2SA1837,BD139,IRFP240,TTC5200 ! If I like what I hear and decide to continue then I'll get more boards made and try different transistors also. TTC 's are Chinese made but it is a Toshiba product. I don't see why they should be poor in any way. I have genuine 2SC5200's and 2SC3281's also !
Will also do tests with different input caps. I have a small range of them !
And the FX8? ......Maybe ! It is in my field of vision along with the unfinished P3A and CFH7 projects !🙂
I often just fit everything to a heat sink and then after testing it often goes into storage !🙂
The urge to keep trying different circuitry expecting something better will be possible , is like a virus without an "antidote" ! 😀 Can't get away from the affliction ! Very expensive pleasurable illness !🙂
I want to put a protection relay on my board along with the PSU caps. Or maybe I'll just use my external PSU cum protection board to save on time. To do a rough cut (!) I'll make one board using the laser printer method. That needs lots of rework but is faster than going to a board house.
I will use the following...( just because I have them !) 2SA992, 2SC1845, 2SA1837,BD139,IRFP240,TTC5200 ! If I like what I hear and decide to continue then I'll get more boards made and try different transistors also. TTC 's are Chinese made but it is a Toshiba product. I don't see why they should be poor in any way. I have genuine 2SC5200's and 2SC3281's also !
Will also do tests with different input caps. I have a small range of them !
And the FX8? ......Maybe ! It is in my field of vision along with the unfinished P3A and CFH7 projects !🙂
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Onsemi NJW's work very well too. That's what I am using.
I have the same affliction. Most amps come in and out over weeks and only one has made it to a case. It's fun and not too expensive if one stocks up on parts ahead of time. Most amps can be built for $10 to $20 in parts now.
I have the same affliction. Most amps come in and out over weeks and only one has made it to a case. It's fun and not too expensive if one stocks up on parts ahead of time. Most amps can be built for $10 to $20 in parts now.
Hi Ashok and X.
Thanks for kind reply.
Amp in last pic is a older MJ Magazin amp with LM biased to 0,5A and plays
with silent dark background- its different.
Yes- we are all caught in a crazy fever race in building new coming out very
interesting new ideas since last two years here- many of them. 😱 🙄
Yesterday i have read a PDF from Toshiba- they have constructed since 2015
a new TO-3P SC5200 Typ and have ordered a pair in digikey shop than.
So X we can compare that new ones to NJW too now.
And finalizing the Quasi plays after two days more in use bit more pleasing.
Thanks for kind reply.
Amp in last pic is a older MJ Magazin amp with LM biased to 0,5A and plays
with silent dark background- its different.
Yes- we are all caught in a crazy fever race in building new coming out very
interesting new ideas since last two years here- many of them. 😱 🙄
Yesterday i have read a PDF from Toshiba- they have constructed since 2015
a new TO-3P SC5200 Typ and have ordered a pair in digikey shop than.
So X we can compare that new ones to NJW too now.
And finalizing the Quasi plays after two days more in use bit more pleasing.
BanglaH,
What is your detailed opinion of quasi amp sound? I don't think you commented yet? I like mine quite a lot. One of my top 4. 🙂
What is your detailed opinion of quasi amp sound? I don't think you commented yet? I like mine quite a lot. One of my top 4. 🙂
How about some Sanken BJT? Can we use them without having to change parts, as a drop in? Like Sanken 2SC2922?
Guys, the NPN output isn't particularly critical, although it doesn't need to be reasonably fast (fT 30-50Mhz) unless you are prepared to experiment with different driver types and local compensation.
Nice work, Max. Seems to me the quasi has attracted some very good builders!
Is it your best sound yet?
The harmonic profile of this quasi is high at H2 and H4, which I have found give warmth and 'body', a sense of solidity, a bit like a strong tube amp.
Hugh
Is it your best sound yet?
The harmonic profile of this quasi is high at H2 and H4, which I have found give warmth and 'body', a sense of solidity, a bit like a strong tube amp.
Hugh
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Oh, no! My builds are always full of macgyverisms.
I need to solder the output transistors and output coil and resistor.
I'm really curious about what comes next!
As promised
It seems a bit quiet here,so let get to more quasi.I`ve got a surprise and i think you will like it.The layout was promised last week and i`ve been trying to upload since last week Tuesday on my cellphone.Definitely a nightmare.
Without further ado,let`s get cracking.
First a thanks to everyone for the positve feedback.I`ve made a couple of changes which i think is for the better.
Let`s not drag this out and let the layout speak.
Regards
phunk
ps:There are gerbers,pdf`s and a Sprint lay file of each version in the zip files.
It seems a bit quiet here,so let get to more quasi.I`ve got a surprise and i think you will like it.The layout was promised last week and i`ve been trying to upload since last week Tuesday on my cellphone.Definitely a nightmare.
Without further ado,let`s get cracking.
First a thanks to everyone for the positve feedback.I`ve made a couple of changes which i think is for the better.
Let`s not drag this out and let the layout speak.
Regards
phunk
ps:There are gerbers,pdf`s and a Sprint lay file of each version in the zip files.
Attachments
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