Toshiba is not so forgiving with models, I have search and don,t find them, but she are good for audio and have low gate capacity. with 1 ma current you need that, I hope dat the real wordl is like the sim world, then you have the first amp who has low distortion even on high fr, I have tryed your design on 30 Khz, even there low fr.
ohh sorry, yes, now you now why she don,t supply models, a shame for such company.
I would have tried these if it weren't for their low breakdown voltage of 60V.
I did however try the 10N20/10P20 lateral as drivers and that worked out bad.
I looked for spice models of those 2SK213/76 pairs but they seem to be broken, found them on this site also. I think the first version is going to receive the 510/9510 pair as initially intended - so far they provide the best behaviour as driver buffer.
ZVN/P3310A version has 100V Vds. Worth to try, due to low capacitance.
What I might say is that in low voltage version fetzilla works very nice with BSS84P (which is very similar to ZVP) even when running v. low current on VAS due to it's limited power dissipation)
Amplifier Testing with Sawtooth signals
[/QUOTE] Kenatoken ...Okay guys, MacGyver time. I put together this simple but effective square wave generator. It can also provide triangle output . . . [/QUOTE]
I found very interesting article about amplifier testing with sawtooth signals
very informative beside square wave testing. It tels much more infos then a single square impulse.
Very interesting reading, and You already made a new test generator, this article should be of good support to the deff. conventional square wave testing practice. . .
[/QUOTE] Kenatoken ...Okay guys, MacGyver time. I put together this simple but effective square wave generator. It can also provide triangle output . . . [/QUOTE]
I found very interesting article about amplifier testing with sawtooth signals
very informative beside square wave testing. It tels much more infos then a single square impulse. Very interesting reading, and You already made a new test generator, this article should be of good support to the deff. conventional square wave testing practice. . .
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In the system under applied BSS84P
Prosty ciekawy wzmacniacz
The following measurements:
Mach Audio - Profesjonalny Sprz?t Audio
Despite the*low*current*VAS*sensational*sound and measurements.
Prosty ciekawy wzmacniacz
The following measurements:
Mach Audio - Profesjonalny Sprz?t Audio
Despite the*low*current*VAS*sensational*sound and measurements.
Thanks! I have known triangle/saw waves had lots of potential for visual testing purposes, but I haven't gotten around to experimenting. First one needs a suitable signal generator. Square waves can almost perform the same function as sawtooth, but half of the spectral components are missing.
Today I have removed the regulators. The bass and midrange were clearer, but the soundstage had no depth and the spatial illusion was no longer believable. The configuration I had before, with just the one small K-multiplier to filter the input and VAS, gives a really good spatial illusion of depth. Harmonica is solidly centered in front of me, instead of flying around the room. Try it! Download "Aria" from here:
High Resolution Music DOWNLOAD services .:. FLAC in free TEST BENCH
The samplerate converter they used is not very good, as you can see if you compare SOX sonograms. Therefore I suggest you download the high-samplerate recording, and use an FFT-based resampler, if you can find one.
The vocals are not as "soulful", the bass not as authoritative as when using the regulators. I suspect this can be fixed without losing the spatial depth, but I don't know. Spatial depth makes the amplifier very relaxing and natural to listen to.
- keantoken
Today I have removed the regulators. The bass and midrange were clearer, but the soundstage had no depth and the spatial illusion was no longer believable. The configuration I had before, with just the one small K-multiplier to filter the input and VAS, gives a really good spatial illusion of depth. Harmonica is solidly centered in front of me, instead of flying around the room. Try it! Download "Aria" from here:
High Resolution Music DOWNLOAD services .:. FLAC in free TEST BENCH
The samplerate converter they used is not very good, as you can see if you compare SOX sonograms. Therefore I suggest you download the high-samplerate recording, and use an FFT-based resampler, if you can find one.
The vocals are not as "soulful", the bass not as authoritative as when using the regulators. I suspect this can be fixed without losing the spatial depth, but I don't know. Spatial depth makes the amplifier very relaxing and natural to listen to.
- keantoken
Yes youd be infringing if the part following the source follower Fet is a BJT. It applies to various combinations including folded cascode. As you use a Fet there is no problem and even less as its a diy project, not commercial undertaking if you decided to go with BJT. Note that this is only applies to the vas stage. But then Mikelm said it, I dont think the patent is valid anymore but I must correct, its from 1989. Anyway the patent was violated by a commercial design some years back but I think the two companies involved never even knew about what was happening. When you have a patent you kind of have to police it or its of no use.
The 2sk213/2sj73 pair are excellent pair to drive output BJTs and might be for driving output Fets too, Sony uses vertical Fets driving output Fets in their more recent top of the range amps.
Getting hold of P Jfets is a problem indeed, it can be done if its a oneoff amp, someone will always part with a pair or two for a price.
I dont know how your squarewave is looking but maybe you could start a new thread as its offtopic here and show some sim results. I wouldnt trust too much in these because of the models but it would be interesting. Sony s top of range amps are using similar setups, asymmetrical though. full Fet designs from input to output and after hearing one of them I must say Im impressed.
so is Borbely.
Can anyone give us a link to his old site and all it's wonderful information, via some archive links?
Borbely s designs are mostly symmetrical and of so-called current feedback type, I cant remember now if he ever used LTP type circuits, he has my highest respect. I have seen him active here a time or two and it would be great if he could participate and impart some of his knowledge and know-how on the forum.
Andrew, if there is some paper or document that he published that you need send me a pm, I might have it.
Andrew, if there is some paper or document that he published that you need send me a pm, I might have it.
Hi,
I have lot of Borbely'e works & papers. I have even create spice simulation for most of them, and indeed they are very promising. However there are some tricky parts.
I have few boards for one of his I/V converters (based on discrete opamp). Slightly modified in case one will find difficult to find proper cascoding FETS with sufficient Vds at required Ids. Unfortunatelly have no time to build one because lack of time... But will do it before end of the year ;-)
Erno uses both LTP and current feedback. The second one mainly for buffers.
I have lot of Borbely'e works & papers. I have even create spice simulation for most of them, and indeed they are very promising. However there are some tricky parts.
I have few boards for one of his I/V converters (based on discrete opamp). Slightly modified in case one will find difficult to find proper cascoding FETS with sufficient Vds at required Ids. Unfortunatelly have no time to build one because lack of time... But will do it before end of the year ;-)
Erno uses both LTP and current feedback. The second one mainly for buffers.
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current feedback is the best way to do it, bandwith is independent with it, and so a very fast and relaxing amp, i have tryed it in the past and it has a 3D sound as the high end store owner says where it was tested, only the more difficult offset stability is a issiue but easy to work around with a good opamp.
Hello Andrew
Here is the link to an archive of the Borbely web site:
Internet Archive Wayback Machine
Bye
Gaetan
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Andrew,
try this link: http://web.archive.org/web/200012041926/http://www.borbelyaudio.com/
But a lot of images are missing.
Best regards - Rudi_Ratlos
try this link: http://web.archive.org/web/200012041926/http://www.borbelyaudio.com/
But a lot of images are missing.
Best regards - Rudi_Ratlos
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