Hi Valery,yes i will do this and post the results soon.
Τake into account that in the above new test I left unconnected the divider GND from the amplifier side.
In post#1428 results are much worse (gnd loop)when divider's GND was connected(except STEPS test).
Maybe i must repeat the STEPS test with dividers GND connected.
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Disconnected divider GND on the ampligier side is fine - that's the approach I also used to avoid the gtound loop 😉
That damned computer thermal paste is non conductive when using a meter on a small dab but contains small metal particles that when pressed tightly against the heatsink can form a short circuit. I ruined 2 mosfets and had to sand the heatsink to remove the residue. If the paste isn't white don't use it
I stay away from ones with silver content, in a case I got away with just loud humming.
High quality white paste (usually ceramic) can reach high thermal conductivity, e.g. Fischer Elektronic paste have an impressive 10W/mK but it's quite expensive
I came across ArcticSilver Ceramique 2 which is quite nice although I have no specs
High quality white paste (usually ceramic) can reach high thermal conductivity, e.g. Fischer Elektronic paste have an impressive 10W/mK but it's quite expensive
I came across ArcticSilver Ceramique 2 which is quite nice although I have no specs
Hi Valery,can you suggest any CFA IPS improvement(picture No 1) looking at the sound card loop test(Picture No 2)?
Picture No 3 is the VFA IPS.
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AX-Deluxe
A long time ago Jeff send to me a varius IPS and many parts.
As some parts are missing i had try to collect some of them but without success.
When i looked again i seen that maybe i can try this IPS,AX-Deluxe.
I will apreciete (as many parts are smd) if we can examine for posible changes when the Power Supply is +/-50V DC
I will try MAT02 in Q1,Q4 position.
I have on hand a 2SK146 GR, if this would be suitable for the same position.
A long time ago Jeff send to me a varius IPS and many parts.
As some parts are missing i had try to collect some of them but without success.
When i looked again i seen that maybe i can try this IPS,AX-Deluxe.
I will apreciete (as many parts are smd) if we can examine for posible changes when the Power Supply is +/-50V DC
I will try MAT02 in Q1,Q4 position.
I have on hand a 2SK146 GR, if this would be suitable for the same position.
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We have a new amplifier for you to test. Give me a list of what you are missing and I'll send you a package. The 2N5089 is an excellent device. I would recommend staying with that.
Good!🙂🙂🙂
Unfortunately i have on hand only the 2N5088,3 pieces only,no way for matching😱
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Hi Thimios!
Coming back to your question, the only value you need to adjust for +/-50V rails is R18 = 24K (instead of 33K for +/-70V).
Cheers,
Valery
Coming back to your question, the only value you need to adjust for +/-50V rails is R18 = 24K (instead of 33K for +/-70V).
Cheers,
Valery
It actually adjusts the current through D3, D14 LEDs - voltage references, keeping around 1.7...1.8V forward voltage in a rather wide range of standing currents. So, it will still work as is with 2.9mA through those LEDs, instead of 4mA, as designed initially. 24K will just bring that current back to 4mA 😉
MAT02 looks good in general, but a rather old one - as already mentioned.
2N5089 is a well-tested one and is perfect for the purpose. Take a well-built VHex+ amplifier - it's practically impossible to hear if the amp is on or off unless you see the light on the front panel - at 29db gain, it's just dead quiet.
2N5089 is a well-tested one and is perfect for the purpose. Take a well-built VHex+ amplifier - it's practically impossible to hear if the amp is on or off unless you see the light on the front panel - at 29db gain, it's just dead quiet.
jFET pair is also a cool test, but it will require degeneration decrease - give me some time.
OK, for 2SK146:
- R6, R10 = 22R
- C2 = 100pF
Measured performance at 1 KHz is going to be roughly the same, distortion at 20KHz will be roughly doubled/tripled. Although, it will be interesting to know your listening impressions, as well as its performance from the noise point of view.
- R6, R10 = 22R
- C2 = 100pF
Measured performance at 1 KHz is going to be roughly the same, distortion at 20KHz will be roughly doubled/tripled. Although, it will be interesting to know your listening impressions, as well as its performance from the noise point of view.