Good afternood again,
I tried what you said Salas and measured the output of my digital source. I'm not sure how to measure but heres a wave in the 2 V pk-pk region (Fight it back with Accept😀)
Btw and OT. I fixed the jumpy right channel so its calm again. I also did some squarewaves. It had a nasty overshoot in the Dynaco A-410 OPTs. I clamped 1500 pF over the feedback resistor and viola.
First I thought the listening experience had gone duller, but then I realized I had just raised the level of "nice listening volume". With 1-2 clicks more volume, which for me usually gets decided by what level of high mid I think is nice at the moment, I had the nice experience back, with a much richer kick-bass than before. The amp went calmer and nicer.🙂
I tried what you said Salas and measured the output of my digital source. I'm not sure how to measure but heres a wave in the 2 V pk-pk region (Fight it back with Accept😀)
Btw and OT. I fixed the jumpy right channel so its calm again. I also did some squarewaves. It had a nasty overshoot in the Dynaco A-410 OPTs. I clamped 1500 pF over the feedback resistor and viola.
First I thought the listening experience had gone duller, but then I realized I had just raised the level of "nice listening volume". With 1-2 clicks more volume, which for me usually gets decided by what level of high mid I think is nice at the moment, I had the nice experience back, with a much richer kick-bass than before. The amp went calmer and nicer.🙂
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That's like wide band noise. In digital you will see much wide band noise on a scope if not band limiting at 20kHz with a steep filter. Especially in cheaper PC audio cards.
The digital audio chips push the noise out of the audio band but the scope catches it anywhere of course.
Congrats on sorting out the amp. You always look forward in testing for such things like overshoot before first listen ever happens I see.😀
P.S. The amp glows fantastically.
The digital audio chips push the noise out of the audio band but the scope catches it anywhere of course.
Congrats on sorting out the amp. You always look forward in testing for such things like overshoot before first listen ever happens I see.😀
P.S. The amp glows fantastically.
Well actually a squarewave can look pretty ugly and the amp can still be nice to listen to, but in this case I think it was favourable to knock some ringing off.
I only have a 20 MHz limiter on the Tex. Can I plug some cap over the 100k resistor?
This is a flac song. Havent done so many. DSO, isnt that scope?
I only have a 20 MHz limiter on the Tex. Can I plug some cap over the 100k resistor?
This is a flac song. Havent done so many. DSO, isnt that scope?
Yea thanx, you have never seen a 12AX7 glow like that have you? I darkened the room and shot woth long shuttertime leaning on a stick. Hence the shaky pic🙄
Accept Fight Back part so thrash metal it looks like random noise. Even on such loud music you get 700mV RMS. So the Eagles Hotel California was near 370mV RMS max is logical on my test too. DSO is your scope. i.e. digital storage oscilloscope. If you will measure with and without some RC filter set at 20kHz on speedier than audio band time setting on the scope you will have an idea of the Focusrite noise. But you won't be hearing or changing that, just curiosity.
P.S. Yesterday I had a good dBSPL helping by spending 4 hours in a 25 yrs birthday local pioneer stoner band's sold out gig. With the assorted HC support bands etc.😀
P.S. Yesterday I had a good dBSPL helping by spending 4 hours in a 25 yrs birthday local pioneer stoner band's sold out gig. With the assorted HC support bands etc.😀
So not even in loud metal music you get 2V RMS=5.66V pk-pk from your FLAC on your Focusrite. More like 700mV RMS. The Itch + Dyna gain scheme looks more compatible to you now?
Very much so sir. I had no idea how to compare the two ways of declaring output before this experience. Thanks! Gonna read kiddo to sleep now. Focusrite is by the DSO if you want me to make more measurs later.
It would be handy again when finished with the TT and phono to compare same song from vinyl and FLAc. In my experience you get +/-3dB play between quieter/louder CDs and an average vinyl cut on same volume knob position for -10dBV nominal cartridge and phono gain scheme. Only problem is when the general gain structure in the system (speakers included) is insufficient. It should be always based on -10dBV sourcing for home Hi-Fi in my view. You already saw the Eagles on FLAc, imagine cool Jazz or soft Classical passages. 2VRMS is not gonna happen unless in pro standard taken from both XLR polarities. Even there it will be rare as AVG. 1.23VRMS or +12dBV more than in Hi-Fi on average.
Well yes, scope has two channels and I have several records on both flac and vinyl.
Today I found two feasable PSU trannys. One that outputs around 260 VAC 90 mA that could suite the Itch alone. I also found another that I measured 277 VAC loaded to 190 mA. The latter could serve an integrated Itch/6V6 pre unity gain with alot of headroom for SSHVs.
Havent made up my mind yet but leaning on integrated. Opinions?
Today I found two feasable PSU trannys. One that outputs around 260 VAC 90 mA that could suite the Itch alone. I also found another that I measured 277 VAC loaded to 190 mA. The latter could serve an integrated Itch/6V6 pre unity gain with alot of headroom for SSHVs.
Havent made up my mind yet but leaning on integrated. Opinions?
If the trafos are away, the rails separate, and the grounding schemes distinct & clean, phono and line can of course share the same roof.
Yes it will be 2-box solution with tranny, first caps and eventual chokes in one and tubbies and SSHVs in the other. Searching for stepped attenuators, if I find a relay one that fits the 6V6 grids I'll implement that to.
Btw I found two matching clear top RCA 6CG7 also. Will build protoboard with novals and octals next to eachother so I can test 6SN7, 6CG7 and E88CC quick and easy. Maybe on big tubbies also for testing 6V6 and EL90.
Meaning you dont think I can have both 6V6 anodes and the Itch top tubes on the same rail?
I was thinking them top tubes have so good PSSR as current sources for the Itch that it wouldnt affect the performance. No?
Could also test with a choke inbetween.
I would prefer testing some means of isolation between the 6V6GT line stage feed and the rest at least. If to start with a shared rail. The Itch has enough PSRR for Merlin to had stayed hum-less without a reg until fixed but he also reported a very noticeable quality jump when restored.
I could test with something like a Hammond 154E, 20H, 20 mA, 1666 DCR and a large filmcap or low DCR lyt inbetween. What gets lost is the fine Z out from the regs, but I dont know if it affects a mu-follower. Does it?