,but the schematics are great.Should be sound very nice.
I only tried the All Fet Power Amp output Statge board EB-1199/114 with components and everything was perfect (all closely matched transistors, which is the main reason I bought the kit).
I would expect the same quality of kits for buffer units but I have not tried.
You can find a lower price Borbely kit from http://www.welbornelabs.com/classa.htm
but I could not get the schematics from Melbourne. It is not a buffer but a line amp (which could probably be set with low gain). I have not ried it either because I need the schematics first.
By the way Erno Borbely is the designer of the old Hafler DH-200/220 amps.
Good luck
I would expect the same quality of kits for buffer units but I have not tried.
You can find a lower price Borbely kit from http://www.welbornelabs.com/classa.htm
but I could not get the schematics from Melbourne. It is not a buffer but a line amp (which could probably be set with low gain). I have not ried it either because I need the schematics first.
By the way Erno Borbely is the designer of the old Hafler DH-200/220 amps.
Good luck
Hi John-china,
TIM is a misnomer for Slewing Induced Distortion (SID). Robert Cordell debunked this in "Another View of TIM" Audio Feb1980.
Any amplifier that has enough slewing rate to produce a 10KHz full output sinewave will not suffer from SID (or TIM) on music.
Open loop bandwidth has nothing to do with it or integrated op-amps with 10HZ open loop BW and 120 dB gain would suffer from it. But they don't because the signal handling in the individual stages is enough to ensure they do not overload.
In a power amplifier of output 50V, the slewing rate need only be 3V/us to be free of this type of distortion. Designers usually ensure is is 3 to 10 times this so THD is low at HF. Emitter degeneration of input stages and higher currents in successive stages are the usual methods.
Hope that helps,
Cheers,
Greg
TIM is a misnomer for Slewing Induced Distortion (SID). Robert Cordell debunked this in "Another View of TIM" Audio Feb1980.
Any amplifier that has enough slewing rate to produce a 10KHz full output sinewave will not suffer from SID (or TIM) on music.
Open loop bandwidth has nothing to do with it or integrated op-amps with 10HZ open loop BW and 120 dB gain would suffer from it. But they don't because the signal handling in the individual stages is enough to ensure they do not overload.
In a power amplifier of output 50V, the slewing rate need only be 3V/us to be free of this type of distortion. Designers usually ensure is is 3 to 10 times this so THD is low at HF. Emitter degeneration of input stages and higher currents in successive stages are the usual methods.
Hope that helps,
Cheers,
Greg
I have many of Borbely's kits. The SB1 is an exceptionally good buffer. As is the SB2.
They both deserve the best PS one can get, and the 254 is such a PS.
If you search this forum, you can find threads on both the SB1 and the 254 by me.
The phono amp I am planning to buy from B. is his new one called /420 (an improved 419).
Sigurd
They both deserve the best PS one can get, and the 254 is such a PS.
If you search this forum, you can find threads on both the SB1 and the 254 by me.
The phono amp I am planning to buy from B. is his new one called /420 (an improved 419).
Sigurd
biovizier said:
Erno has his JFET/MOSFET thing and this is implemented to 100% whether this is right or wrong. I like this. All his designs are "approved" by me, nothing weird, good engineering. The only objection I have is possible his handmade pcb layouts. Even a student nowadays handles Eagle or whatever to do real nice looking pcb's. For the prices he is charging I at least would have demanded highest professional pcb's both in looks and in performance. The pcb's he is offering now looks a bit "vintage". I haven't examined the pcb layout itself, how good the are in the electrical sense. I'll believe they are pretty good but I don't know if they reach "Spitzenklasse".biovizier said:
I haven't mentioned the prices: 850 EUR/USD for a kit
The 320 amd the 420 are rather similar. The most dramatic difference is that the 320 uses a MOSFET on the ouptut while the 420 uses JFETs.
The 320 can probably handle lower output level MC pickups.
The 320 is a bit pricey for my taste. I hardly play any LPs but when I do I want a very, very good RIAA amp!
Yes, I use the 254 PS and also have the 319. Nowadays, however, I use Per-Anders RFB02 for rectifying purposes.
http://home.swipnet.se/~w-50719/hifi/rfb02/index.html
used with either soft FREDs or Schottky diodes.
I just ordered another 254 which I will use for another line amp.
Borbely has 10% discount in December!
Sigurd
The 320 can probably handle lower output level MC pickups.
The 320 is a bit pricey for my taste. I hardly play any LPs but when I do I want a very, very good RIAA amp!
Yes, I use the 254 PS and also have the 319. Nowadays, however, I use Per-Anders RFB02 for rectifying purposes.
http://home.swipnet.se/~w-50719/hifi/rfb02/index.html
used with either soft FREDs or Schottky diodes.
I just ordered another 254 which I will use for another line amp.
Borbely has 10% discount in December!
Sigurd
Re: Re: Borbely Audio
The circuit boards are not very pretty. Also, single sided. Nice heavy traced, double sided board would be a big improvement.
The 419 was 300.00 USD Delivered.
George
peranders said:
Erno has his JFET/MOSFET thing and this is implemented to 100% whether this is right or wrong. I like this. All his designs are "approved" by me, nothing weird, good engineering. The only objection I have is possible his handmade pcb layouts. Even a student nowadays handles Eagle or whatever to do real nice looking pcb's. For the prices he is charging I at least would have demanded highest professional pcb's both in looks and in performance. The pcb's he is offering now looks a bit "vintage". I haven't examined the pcb layout itself, how good the are in the electrical sense. I'll believe they are pretty good but I don't know if they reach "Spitzenklasse".
I haven't mentioned the prices: 850 EUR/USD for a kit
The circuit boards are not very pretty. Also, single sided. Nice heavy traced, double sided board would be a big improvement.
The 419 was 300.00 USD Delivered.
George
Re: in EB693/129
I think you refer to the Servo DC-50.
Erno Borbely more recent designs have also different open loop frequency or gain. For example, the EB-1198/116 ALL-FET line amp has 67db open loop gain (medium open loop gain compared to 85db) with open loop frequency close to 20 KHz! Its open loop THD at 3V rms is 0.095% at 10 KHz.
john-china said:
I think you refer to the Servo DC-50.
Erno Borbely more recent designs have also different open loop frequency or gain. For example, the EB-1198/116 ALL-FET line amp has 67db open loop gain (medium open loop gain compared to 85db) with open loop frequency close to 20 KHz! Its open loop THD at 3V rms is 0.095% at 10 KHz.
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