The 118 is notched for THD measurements and FFT analysis, 0.0015% 200Hz-10kHz. Sinewave output only probably. The Instek is to see wiggles and rise times and HF frequency limit. First is up to 200kHz only, the other one is 3MHZ. C1-93 that Stajo has and other stuff were done in Vilnius and Minsk back in the day so there may be interesting NOS around in your area. Soviet stuff used some weird BNC like but not exactly BNC fitting some times, so watch that also.
My X1 buffer with resistor load is very little microphonic so there must be a way. Sound has to clear out of the echoes.
Phase splitter? XLR to drive? If you mean Y splitter to drive two things off one output, then 100R in line resistors after the output capacitor.
For driving balanced amp. Prefer balanced out and in and would like to add option if possible. Was thinking of Sy' Impasses phase splitter as option, but could always just use transformer. Tough cause I may not need it, but I don't know till I try. Pulled out the pre yesterday. All this smoke gave me the itch to finish the redo. Ordering parts now.
I will take it in stages to see what I will find out. I worked on shielding today but I didnt get it to a listening ready state beforeI had to move over to a mandatory beershooting/pooldrinking activity with workbuddies. More story tomorrow maybe
A 1660 gaped for around 40 might be your choice for 6v6. Enough Z and voltage for Pass amps. Per makes them as you want them at no extra charge
I will keep current version SE and try another with diff stage. Got enough tubes, so why not.
OK but mine is the bootstrapped one with Teflon cap on input also keep in mind.
For general use function generator you seldom get less than -55dBc distortion. Those equipment are not specialized for THD measurements. They are to feed many waveform types over a large bandwidth so to monitor the time domain. Many budget to enough hundred $ DDS have jitter especially in the kHz. That Siglent double output with impressive features, color menu screen and extended bandwidth many got to regret for instance. The squares were dancing the lower they went in frequency. LeCroy sells it over 1000$ in base model black color with its badge on...That Instek is dependable and I say so bcs I had used it.
how about using a simple split load phase splitter
(I have seen one converting SE signal to balanced with a jfet or BJT)
and its so simple you can mount it directly on the XLR plug
A chief developer and good friend of mine once told me "-A fool with a tool is just a bigger fool" when I installed some version of Visual Studio to play with. He was ofc right in that and it is definately an expression that describes me well atm.
A week or two ago and some 100ish posts away I was concerned with a "B+ ripple" that later showed to be unexisting. I had hum in the speakers, the DMM and my lousy scope pointed on that.
After using a proper scope I could conclude that its not in B+, its rather in filaments or in EMI. Trying an extremely overkilled LM350 reg on the filaments took hum down to listenable levels but not to a level that makes measurements justice.
I now used a passively filtered DC arrangement with uV ripple and hum went up again to audiable levels in the sofa. The cathode choked 6V6 starts to act like an extremely sensitive DHT with microphonics and I think I would need something like a Coleman reg to solve this, and I dont have any. I have a bunch of 3,5 kg 170ish mH 1,5 ohm chokes in the 3 amp region that might take care of that but I'm not in the mood to try that.
Well. Still confused but on a higher level and hungover too. Shall we try a choke loaded anode follower maybe? I think I can get some 280ish B+ in this config with SSHVs.
A week or two ago and some 100ish posts away I was concerned with a "B+ ripple" that later showed to be unexisting. I had hum in the speakers, the DMM and my lousy scope pointed on that.
After using a proper scope I could conclude that its not in B+, its rather in filaments or in EMI. Trying an extremely overkilled LM350 reg on the filaments took hum down to listenable levels but not to a level that makes measurements justice.
I now used a passively filtered DC arrangement with uV ripple and hum went up again to audiable levels in the sofa. The cathode choked 6V6 starts to act like an extremely sensitive DHT with microphonics and I think I would need something like a Coleman reg to solve this, and I dont have any. I have a bunch of 3,5 kg 170ish mH 1,5 ohm chokes in the 3 amp region that might take care of that but I'm not in the mood to try that.
Well. Still confused but on a higher level and hungover too. Shall we try a choke loaded anode follower maybe? I think I can get some 280ish B+ in this config with SSHVs.
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I have a 6V6 pre running basic setup with just current regulated heaters and it works perfectly.
Indirekt heated tubes aren´t to fuzzy about the heating supply.
I usually split the contraption that´s making my life miserable and put the individual PSU´s a bit apart and then start investigating what´s the source of the problem.
Wound components has a bad habit of both sending and receiving a lot of unwanted stuff so just moving things around can sometimes solve it.
Indirekt heated tubes aren´t to fuzzy about the heating supply.
I usually split the contraption that´s making my life miserable and put the individual PSU´s a bit apart and then start investigating what´s the source of the problem.
Wound components has a bad habit of both sending and receiving a lot of unwanted stuff so just moving things around can sometimes solve it.