Yes you can...specially the low noise types...
No ...it will be fine!!
If you want the some operating points change the 2k2 resistor to a 3k3 resistor!And the 6,2k to 9k3(10k will be fine)
Regards
MAT02
Hi guys,
If this on is better I'll use it in the head amp.
If you say no! I'll use the BC550C.
Thanks ones again!
Audiofanatic 😉
Hi guys,
If this on is better I'll use it in the head amp.
If you say no! I'll use the BC550C.
Thanks ones again!
Audiofanatic 😉
Actualy...it does have voltage gain.
At first i though that the input was at le left of the schematic...but after some bourning eyes it look like that the input is at the botom..
In this case we have a paralel comum base transistor stage...and we have voltage gain and no current gain...😉
Hi,
Guess I suffer fron the same eye strain...Yes, you're right.
Still don't like it too much though😀
Anyway, the art is in the execution I suppose....😉
Guess I suffer fron the same eye strain...Yes, you're right.
Still don't like it too much though😀
Anyway, the art is in the execution I suppose....😉
Re: MAT02
Yes is a fine transistor...low noise and in the C version high current gain...
One of my favorits 😉
Audiofanatic said:
Yes is a fine transistor...low noise and in the C version high current gain...
One of my favorits 😉
Audiofanatic
You would be better off with the parallel FET's and an a gain stage vs. the bipolar transistors due to leakage currents. Also, that input cap should be a Teflon or polystyrene.
Tubes or ok but their noise is just to much for me. The transformers I have heard had no balls.
A comman gate fet have a natural low impedance. John Dunlevy used this in an older design and worked well. The parts are much better now.
"This is my Texan answer"
You would be better off with the parallel FET's and an a gain stage vs. the bipolar transistors due to leakage currents. Also, that input cap should be a Teflon or polystyrene.
Tubes or ok but their noise is just to much for me. The transformers I have heard had no balls.
A comman gate fet have a natural low impedance. John Dunlevy used this in an older design and worked well. The parts are much better now.
"This is my Texan answer"
Standard BC transistors are not good for this circuit. For low noise you must use transistors with low rbb. Look at pages of Erno Borbelly or on AD pages.
Hi,
Johnson noise from the tubes in my circuit is the same as a 70 Ohm resistor...
With a CCS on the anode the PSU noise is out of the picture, no cathode resistors either...
It does I/V perfectly well but it relies on the tubes you use and the noise of the JFETs used as CCSs.
Hope you see the humour....😀
Cheers,😉
Johnson noise from the tubes in my circuit is the same as a 70 Ohm resistor...
With a CCS on the anode the PSU noise is out of the picture, no cathode resistors either...
It does I/V perfectly well but it relies on the tubes you use and the noise of the JFETs used as CCSs.
Hope you see the humour....😀
Cheers,😉
Heeeeeeeeeeeeeeeeeeeeeeeeeeeeelp!
Jewilson,
Do you have a schematic?
Thanks.
Audiofanatic 😉
jewilson said:
Jewilson,
Do you have a schematic?
Thanks.
Audiofanatic 😉
jewilson said:
The inpedance looking in the source of a fet is 1/Gm...in a typical fet we have 10mA /volts...
So we have 100 Ohms of input inpedance with the fet stage...
With the bipolar the impedance looking at the emiter is 25/Ic...so as the current in the schematic is 1,1mA we end up with 22 Ohms...
Five times better! 😉
"This is my Portuguese answer!" 😉
Cheers
Hi,
Shall I put you through the thinking?
The ECC88/6DJ8 has some qualities few other tubes posess: it's low noise, has very good transconductance and is linear at Vg=0.
Add to that that it's perfectly happy transforming I/V just like a J-FET, stick a CCS on it's anode and you have what a MC needs...
The I/V is done by the load resistor serving as the gridleak and hey, the tube is forced into current mode operation, elegant and simple.
I use a very low output MC and I can't hear any noise...
Not in my system anyway, at a 92dB/WM I'd expect to hear it yet I don't. No noise and dynamic range to die for.
Cheers,😉
Shall I put you through the thinking?
The ECC88/6DJ8 has some qualities few other tubes posess: it's low noise, has very good transconductance and is linear at Vg=0.
Add to that that it's perfectly happy transforming I/V just like a J-FET, stick a CCS on it's anode and you have what a MC needs...
The I/V is done by the load resistor serving as the gridleak and hey, the tube is forced into current mode operation, elegant and simple.
I use a very low output MC and I can't hear any noise...
Not in my system anyway, at a 92dB/WM I'd expect to hear it yet I don't. No noise and dynamic range to die for.
Cheers,😉
Hi
The ECC 88 with the transconductance of 12,5 ma /volt as a cathode impedance of 80 Ohms...as good or beter than a fet...
cheers 😉
The ECC 88 with the transconductance of 12,5 ma /volt as a cathode impedance of 80 Ohms...as good or beter than a fet...
cheers 😉
Tubos!
Hi Frank,
I'll go for the tube version, eventualy!
But first I would want to know if you can supply the 4 tubes and, what would be the price?
I'm gona use the Raven R2 Tweeter 96db/W/M, instead of the Martin Logans, so, what about het noise of this head amp vs. the Hiraga/Threshold?
Audiofanatic 😉
Hi Frank,
I'll go for the tube version, eventualy!
But first I would want to know if you can supply the 4 tubes and, what would be the price?
I'm gona use the Raven R2 Tweeter 96db/W/M, instead of the Martin Logans, so, what about het noise of this head amp vs. the Hiraga/Threshold?
Audiofanatic 😉
Hi,
We need to look at the tube's transfer curves in the circuit proper, than look at what it's going to see next and how it will look than etc.
I designed it in such a way that the system as a hole is holistic, the preamp can be used for MM cartridges, the MC Hammer + MM preamp work together well too...
Respecting all standards along the way.
In fact I can't think of a single cartridge it can't cater for...
The preamp's output can drive both lowish impedance and long capacitive cable without changing it's frequency response within the audio band and often way beyond.
This set of qualities is why I'd like Audiofanatic to understand that matching commercial product can and often does result in a mismatch...
Not to mention the fact that most commercial designs need to be even more stringent designing their product...
Designing for your own needs is alot easier, believe me.
Cheers,😉
We need to look at the tube's transfer curves in the circuit proper, than look at what it's going to see next and how it will look than etc.
I designed it in such a way that the system as a hole is holistic, the preamp can be used for MM cartridges, the MC Hammer + MM preamp work together well too...
Respecting all standards along the way.
In fact I can't think of a single cartridge it can't cater for...
The preamp's output can drive both lowish impedance and long capacitive cable without changing it's frequency response within the audio band and often way beyond.
This set of qualities is why I'd like Audiofanatic to understand that matching commercial product can and often does result in a mismatch...
Not to mention the fact that most commercial designs need to be even more stringent designing their product...
Designing for your own needs is alot easier, believe me.
Cheers,😉
Hi,
Quit the tube business some years ago but I fully trust Ger Fust who was a customer of mine:
Send him my sincerest regards and ask him to match the tubes to Reference Audio standards...
He'll understand and have a little laugh...
Cheers, 😉
Quit the tube business some years ago but I fully trust Ger Fust who was a customer of mine:
Send him my sincerest regards and ask him to match the tubes to Reference Audio standards...
He'll understand and have a little laugh...
Cheers, 😉
RE:Como agradecerte?
Hi,
Con mucho gusto...No me falta nada, no te preoccupes. 😎
Buenas noches,😉
Hi,
Con mucho gusto...No me falta nada, no te preoccupes. 😎
Buenas noches,😉
Do you have a schematic?
Audiofanatic
I might still have it, however I had this amp back in the late 70's
Audiofanatic
I might still have it, however I had this amp back in the late 70's
analog_sa said:
Parts are gathering for mine... give me a couple years 🙂 to get it finished and i'll comment on how it sounds. The full-diff version lets you run out from the TT in fully balanced mode with absolute phase switching.
dave
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