My experience also, it was not a particularly fussy deal to set that pre. Maybe the choke load idea brings more trouble than benefit...Having the pre for long? I don't remember you posting about it. In what system, any pics?
Well if your ever near the capital your welcome to have a looksie. I have done 5 different PSUs, exhanged all parts every time, used all possible filament feeding I can think of. AC tied to gnd and elevated up to 95 V over gnd and DC regulated in two ways. The 350 reg I used that worked best was one I had in an ECC88 RIAA and it was silent there.
Elevated DC is a thing I havent tried but I dont think it will solve it.
Its a shame since the sound is promising. Transients is almost to much and bass region firm listening to it.
Elevated DC is a thing I havent tried but I dont think it will solve it.
Its a shame since the sound is promising. Transients is almost to much and bass region firm listening to it.
Hi-hat became a new experience with this pre and a 6L6 poweramp. What before was a flat tic is now a complex TZZZ. I hear the cymbals moving.
Stajo, maybe a simple try with resistor load to see if the trouble is choke load related or not?
Elevated heaters is something that makes a difference on indirect heated tubes.
I run them starved to.
Thr pre is right now resting in storage while an old eico saved from a certain death in a dumpster is playing.
I hope one of my friends will give it a new home soon since it´s not even close to medium FI 😀.
I run them starved to.
Thr pre is right now resting in storage while an old eico saved from a certain death in a dumpster is playing.
I hope one of my friends will give it a new home soon since it´s not even close to medium FI 😀.
Play around and try Resistor and CCS load if it is quite then the chokes have to be differently mounted or screened perhaps.
680R/6K8 from cathodes to gnd and 470K in between them to wipers. Even more hum (sharp hum) and same microphonics. Magic in sound gone.
50/100 Hz hum gets rid of edgyness if i connect earthground to chassie, but the warm hum is still there
50/100 Hz hum gets rid of edgyness if i connect earthground to chassie, but the warm hum is still there
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I'll dig that earth grounding of the 6L6 Candela up. As I remember it has a 1 k from signalgnd to earthground. Maybe a dual rectifier instead, what do you think? I have no connectrion between earthgnd and signalgnd in 6V6 now.
Good point. You can send those parts to official US disposal facility.
Your Fets shippped, BTW.
Your Fets shippped, BTW.
Thanks man. I wonder where the iron is. Better check that up. Dude, hum almost went away with my Hafler EL84 and that has earthgnd-signalgnd directconnected. Definately ground related. How do you guys do, earthgnd-signalgnd to pre and power?
That is what I use and I confirmed all harmonic noise is bellow -100dB level ref 0dBV by remeasuring one hour ago with 4 things connected on inputs and the amp wired also. The Tx and AC mains wiring is on same chassis.
You may see one power ground star on (-) of a big PSU cap, then a chassis star near the RCAs, and a common on a copper leaf hanging off a wooden rod near the signal circuits. That signal circuits return points ground connects to the near RCAs signal ground star with a cable. The PSU ground connects there with one cable. The mains earth prong connects to chassis at a point near its entry. The input runs from selector to audio circuitry and to output are 75 Ohm coax. Not the fat variety.
Ok, Ic. The black wires. But how does it relate to poweramp? Does that connect to earthground to? Then you should have a loop.
Btw I'm narrowing up. Almost silent with EL84 now, gonna fix that Candela tomorrow. Dull sound with resistors, going back to chokes.
The power amp on rack now has a system grounding as in blameless amplifier Douglas Self book. There is no loop bcs what I measured for such low harmonic noise was with the amp connected.
