Do you mean using your Pearl PSU to power the BA-3? It certainly has the capacity... I think it's worth trying!
The first 2 things that come to mind -
You'd need a separate regulator for the BA-3.
Getting power from the PSU to the preamp chassis would best be done by a Y umbilical or a daisy-chain.
The first 2 things that come to mind -
You'd need a separate regulator for the BA-3.
Getting power from the PSU to the preamp chassis would best be done by a Y umbilical or a daisy-chain.
hi 6L6 and all,
I have 2 questions regarding building Pearl 2 Phono
1. Instead of using 3300 uF capacitors on C4,C6, C24 Pearl 2 board, can I use 4700 uF capacitors instead? do you see any issues that might affect sonic performance/noise/hum with replacing 3300 uf by 4700 uf ?
2. Since the Pearl 2 design already incooporated its own voltage regulator to have a regulated 24Vdc to the circuit, is it okay if I just use wallwart of unregulated 30 Vdc to feed into DC in ? As this adapter below
30V 2A 60W Switching Power Supply Charger AC Adapter
https://www.amazon.com/Switching-Po...=1477525788&sr=8-2&keywords=DC+adapter+30+Vdc
Please let me know,
Thanks,
Tom
To answer your second part of the question here's the quote from Wayne's paper:
"so feel free to substitute any reasonable supply that delivers the required voltages (28 to 34 volts at 100 mA). You may also elect to use switching supplies, wall-warts, stacked batteries – whatever safely does the job."
Try regulated clean supplies like Salas shunts later to compare.
[QUOTEqwertylI am wondering if my a bit oversized Pearl 2 PSU (transformer 150VA 2x22V, rectifiers and capacitors) can be used for both Pearl 2 and BA-3 front end. Any thoughts? ][/QUOTE]
I've have this setup. I ran into an issue with a ground loop. External PWS gnd is shared to each the Pearl II and BA-3 pre through umbilicals then the interconnects' gnd complete the loop between them. Once I finish upgrading my F5T-v2 to F5T-v3 monos I'm going to try a switch on the Pearl II to break the interconnect grounds. Haven't tested it yet but should take care of the gnd loop and shields still grounded on pre side. (?) Maybe some resistance would be sufficient?
TJ
I've have this setup. I ran into an issue with a ground loop. External PWS gnd is shared to each the Pearl II and BA-3 pre through umbilicals then the interconnects' gnd complete the loop between them. Once I finish upgrading my F5T-v2 to F5T-v3 monos I'm going to try a switch on the Pearl II to break the interconnect grounds. Haven't tested it yet but should take care of the gnd loop and shields still grounded on pre side. (?) Maybe some resistance would be sufficient?
TJ
Yes, thinking about this now - there will be a ground loop... Do I need to connect RCA gnd on both sides (between Pearl 2 and BA-3)?
I suppose I can use input line transformer to break the ground loop, something like Jensen JT-11P-1.
Hello!
I have recently built pearl two, but due to high gain about 66 dB (R14=221 Ohm), I have voltage fluctuation at the test point about +/- 100 mV. Then I have added 400 uF capacitor in series with R14 and got almost zero mV without fluctuations. And i think, why Wayne did not do that in Pearl 2, but did in Aleph Ono. Also it solves problem with very sensitive adjustment of P1 (actually we do not need P1).
Regards, Yuri.
I have recently built pearl two, but due to high gain about 66 dB (R14=221 Ohm), I have voltage fluctuation at the test point about +/- 100 mV. Then I have added 400 uF capacitor in series with R14 and got almost zero mV without fluctuations. And i think, why Wayne did not do that in Pearl 2, but did in Aleph Ono. Also it solves problem with very sensitive adjustment of P1 (actually we do not need P1).
Regards, Yuri.
Stability in the feedback loop
f= 1/(100kΩ*5pF)=2,000,000
adding more capacitance lowers the frequency at which the attenuation occurs.
my Pearl 2 works fine with just 5pF
some folks might argue for "missing pole compensation" -- a topic well beyond the scope of this thread.
What type capacitor did you use? This seems significant, Wayne or anyone else have a comment on this?
Russellc
I like this idea very much
I had more or less scrapped the Pearl RIAA due to the overload problems (with my AT150), but now it might be time to build...
A few questions:
-Does cable and input capacitance play a role in the L/R-loading of the cartridge?
-Is your values directly useable in the Pearl circuit?
I like this idea very much
I had more or less scrapped the Pearl RIAA due to the overload problems (with my AT150), but now it might be time to build...
A few questions:
-Does cable and input capacitance play a role in the L/R-loading of the cartridge?
-Is your values directly useable in the Pearl circuit?
You'll need to determine the inductance of this cartridge -- it isn't the AT150 manual