I am interesting in a few schemes at this site: http://www.borbelyaudio.com .What sort of widespread transistors I can apply instead of J74BL, J79, J103, J148, K216, K246, K982 ?
Please don't waste your time trying to change the parts. They are not easily second sourced. Buy them from Borbely. They will be relatively expensive, but you are in no position to find them much cheaper. In fact, just get a 'kit' from Borbely, and don't waste your time trying to make it on the cheap. You will pay more, in the long run.
AlexO, I did not note previously, that you live in Moscow. I understand now that the cost of these components is very high, especially from Erno, with the rate-of-exchange. I was trying to save others, who might live in Germany or many other places in Western Europe, to not waste their time trying to save a few Euros, but I will tell you the whole situation, in order to help you further.
We have used these devices, that Erno Borbely designs with, and sells, for many years. Once, I had 3000 2SJ79's in my possession along with the complement, the 2SK 216 (I think) . They were burned up in a firestorm, but if I had them today, I could sell them and buy a Porsche with the money. What used to cost 1 euro each, 20 years ago, now may now sell for many, many times more. When you are trying to buy just one to 5 parts, the cost of your purchase is always high, because of the handling cost for the distributor. After all, 1 piece, or 100, or 1000 pieces takes the same processing time. If you can find a cheap distributor, then you will have had better luck than I have, over the years. Give it a try, if you want.
Second, these devices are SOTA, which means the best available, like Porsche or Mercedes. These parts will always cost more than a near equivalent part that is not quite so unique. I cannot personally recommend other parts, because I do not use them, but there are somewhat similar parts available at a reasonable price.
We have used these devices, that Erno Borbely designs with, and sells, for many years. Once, I had 3000 2SJ79's in my possession along with the complement, the 2SK 216 (I think) . They were burned up in a firestorm, but if I had them today, I could sell them and buy a Porsche with the money. What used to cost 1 euro each, 20 years ago, now may now sell for many, many times more. When you are trying to buy just one to 5 parts, the cost of your purchase is always high, because of the handling cost for the distributor. After all, 1 piece, or 100, or 1000 pieces takes the same processing time. If you can find a cheap distributor, then you will have had better luck than I have, over the years. Give it a try, if you want.
Second, these devices are SOTA, which means the best available, like Porsche or Mercedes. These parts will always cost more than a near equivalent part that is not quite so unique. I cannot personally recommend other parts, because I do not use them, but there are somewhat similar parts available at a reasonable price.
Hi John, a Porsche or Mercedes seems to be very cheap in the States. The J79/K216 costs EUR 1,80 in Germany in quantities of 1000. For only $10000 a Porsche, not bad 
You can get them also from Farnell, but the price is higher. Many parts you can get also from Heho if you are confirm with the German language.
You can get them also from Farnell, but the price is higher. Many parts you can get also from Heho if you are confirm with the German language.
hitachi / renesas mosfets
These are very good transistors and I know of no similar device that is close for a drop in replacement.
For lower power devices with even lower capacitance and a little greater transconductance, I would try the Zetex ZVP3310A and ZVP3310A They are capable of about half the power dissipation and 100 volts drain to source. They have a higher turn on votage of around a couple of volts and also need a zener to protect the gate.
http://www.renesas.com/eng/products/discrete/transistor/index.html
Power MOSFET for General Amplifier
http://www.ceitron.com/semi/semi.phtml?part=j79
http://www.ceitron.com/semi/semi.phtml?part=K216
The Borbly kits are expensive and I see no reason for a D.I.Y. not to make his own PCBs or build with point to point wiring. This a big part of the DIY experience. Online design reveiws or pretty common here as well.
I will leave Porsche pricing to someone like say.... Jonathan Carr.......
These are very good transistors and I know of no similar device that is close for a drop in replacement.
For lower power devices with even lower capacitance and a little greater transconductance, I would try the Zetex ZVP3310A and ZVP3310A They are capable of about half the power dissipation and 100 volts drain to source. They have a higher turn on votage of around a couple of volts and also need a zener to protect the gate.
http://www.renesas.com/eng/products/discrete/transistor/index.html
Power MOSFET for General Amplifier
http://www.ceitron.com/semi/semi.phtml?part=j79
http://www.ceitron.com/semi/semi.phtml?part=K216
The Borbly kits are expensive and I see no reason for a D.I.Y. not to make his own PCBs or build with point to point wiring. This a big part of the DIY experience. Online design reveiws or pretty common here as well.
I will leave Porsche pricing to someone like say.... Jonathan Carr.......
Re: ERNO RESPONCE
When is a 400% markup justified?
is 400% a lot? -- consider that for the fickle and not enormous DIY market, you hold inventory which can be obsoleted and is subject to the pricing vagaries of any manufacturer who wants to dump their products, consider that you have to pay $600 per month, or $1200 per employee-month for healthcare in the US, and probably lots more in Europe, that you have telecom fees, rent, returns, deadbeats, etc. 400% isn't necessarily a lot. If you are selling to an OEM in the US or Germany 400% would get you laughed out of the parking lot, OTOH 100 or 200% would be acceptable to a contract manufacturer who has a couple hundred or few thousand devices, wants to be able to get credit and the ability to return product.
If you beg to differ, go out and buy 2000 or 20k pieces and try to part them out.
jewilson said:
When is a 400% markup justified?
is 400% a lot? -- consider that for the fickle and not enormous DIY market, you hold inventory which can be obsoleted and is subject to the pricing vagaries of any manufacturer who wants to dump their products, consider that you have to pay $600 per month, or $1200 per employee-month for healthcare in the US, and probably lots more in Europe, that you have telecom fees, rent, returns, deadbeats, etc. 400% isn't necessarily a lot. If you are selling to an OEM in the US or Germany 400% would get you laughed out of the parking lot, OTOH 100 or 200% would be acceptable to a contract manufacturer who has a couple hundred or few thousand devices, wants to be able to get credit and the ability to return product.
If you beg to differ, go out and buy 2000 or 20k pieces and try to part them out.
About business: Every seller set his own price, high enough to earn money, not too high though. Unfortunately the equation is not totally defined. Lower price may generate higher profit. Compare high CD prices!
I think Erno not have tested his prices.
The disadvantage is that a becoming customer can be "not happy" with the prices because he want the stuff but thinks that the price is a rip-off. Just like Jim here.
I think Erno not have tested his prices.
The disadvantage is that a becoming customer can be "not happy" with the prices because he want the stuff but thinks that the price is a rip-off. Just like Jim here.
I think we all can agree that the prices are amazing, 1299 EUR = 1461 USD is not cheap 
for a phono amp. For this price I would have demanded highest possible quality of the pcb's and CADed also. Maybe even goldplated like the one from HP in the 70's 80's.
http://www.borbelyaudio.com/index22.htm
for a phono amp. For this price I would have demanded highest possible quality of the pcb's and CADed also. Maybe even goldplated like the one from HP in the 70's 80's.http://www.borbelyaudio.com/index22.htm
PerAnders..
I've been scrutinizing Borbelys price list for a little while, and comparing with your own prices.....
Ernos basic kit, 2 PCBs and all semi's are 400€...for your own phono pre you charge 100€ for the PCB only...
Erno's AllFET pre uses 4 sets of 4 matched FETs plus a series of matched pairs. You charge SEK 50, or 7€, for matching of Power FETs. Whether you match high or low power, the job is the same...with your prices, the matching job alone will be appx. 150€, then add basic component price and the waste created with proper matching, it seems to me that your own price is at least as high as Borbelys.
Nichicons, Dale resistors etc. are expensive so are commercially made cabinets, ala Fischer.....
I do agree,- 1300€ is expensive, but I bet if someone bothered to look up all the parts necesseary including the extra overhead foor matching, and add it all together, the total cost will be very close to Borbelys. Then in addition you have a matching job to do....
The AllFET pre relies heavily on matching, as most of Borbelys constructiuons. So does a lot of the Pass amps, although in another direction of philosophy. The AllFET reminds me of the Ono in complexity. Which one is best ?? DOn't ask me,- I don't know yet., but I am currently working on an Ono for myself...........
It seems to me that somebody here are out one a witch hunt, possibly under false flag. I do not think this is proper behaviour in a forum like this,- my personal opinion though!!
I've been scrutinizing Borbelys price list for a little while, and comparing with your own prices.....
Ernos basic kit, 2 PCBs and all semi's are 400€...for your own phono pre you charge 100€ for the PCB only...
Erno's AllFET pre uses 4 sets of 4 matched FETs plus a series of matched pairs. You charge SEK 50, or 7€, for matching of Power FETs. Whether you match high or low power, the job is the same...with your prices, the matching job alone will be appx. 150€, then add basic component price and the waste created with proper matching, it seems to me that your own price is at least as high as Borbelys.
Nichicons, Dale resistors etc. are expensive so are commercially made cabinets, ala Fischer.....
I do agree,- 1300€ is expensive, but I bet if someone bothered to look up all the parts necesseary including the extra overhead foor matching, and add it all together, the total cost will be very close to Borbelys. Then in addition you have a matching job to do....
The AllFET pre relies heavily on matching, as most of Borbelys constructiuons. So does a lot of the Pass amps, although in another direction of philosophy. The AllFET reminds me of the Ono in complexity. Which one is best ?? DOn't ask me,- I don't know yet., but I am currently working on an Ono for myself...........
It seems to me that somebody here are out one a witch hunt, possibly under false flag. I do not think this is proper behaviour in a forum like this,- my personal opinion though!!
Jewilson, it is a serious breach of netiquette and privacy to publish an email without the permission of the sender. I've split off your offending post and the commentary and sent it all to Texas. After discussion among the mods, we are imposing a 2 day SinBin sentence, suspended since it's your first offense. We reserve the right to "unsuspend" it, if we feel that's appropriate.
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