Aiming for 1volt as in the build guide. Is it safe to increase bias?
Now my BA3 is up to 1V bias. Output 2V from 1V sine wave. I use original schematic except for P1 and P2, they are 1k. Shouldn’t output be 3V? Without tinkering with P3 I have THD% 0,4. It sounds detailed and controlled but there is some something missing. I can only describe it as ”it’s not B1K”. Do I miss some 2H? Du anyone have suggestions how to tweak BA3 to a friendly tone?
How much 2H is reasonable? The big >3H, are the only in my not so sophisticated oscilloscope?
Volume pot before or after is next on the test list.
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show me schm your'e using and write what differences in parts are exactly
edit: in fact , there is no need
increase gain simply increasing value of final I/V resistor
you can't change THD Spectra without trying with P3 , and you must do that , to find setting you prefer sonically
if B1 is positive reference to you, you need to find setting with 2nd harmonic dominant and lesser THD overall
edit: in fact , there is no need
increase gain simply increasing value of final I/V resistor
you can't change THD Spectra without trying with P3 , and you must do that , to find setting you prefer sonically
if B1 is positive reference to you, you need to find setting with 2nd harmonic dominant and lesser THD overall
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search for threads about THD Spectra, FFT measurements
decent soundcard and few progz will do the job, once you get (not so complicated) routine
decent soundcard and few progz will do the job, once you get (not so complicated) routine
Gents! I wonder if this a suitable PSU for this pre.
https://www.google.com/url?sa=t&sou...Vaw1BQt8xUZ5NByPAEWKp6PRt&cshid=1587221127472
Thanks in advance ��
https://www.google.com/url?sa=t&sou...Vaw1BQt8xUZ5NByPAEWKp6PRt&cshid=1587221127472
Thanks in advance ��
I have used this PSU to wonderful effect -
Dual/Bipolar LV-Reg
And I like this transformer, it's much more current than needed, but it's the smallest they make that is shielded. 🙂
AS-0518 - 50VA 18V Transformer - AnTek Products Corp
Dual/Bipolar LV-Reg
And I like this transformer, it's much more current than needed, but it's the smallest they make that is shielded. 🙂
AS-0518 - 50VA 18V Transformer - AnTek Products Corp
Oh, good point!! This is the BA-3 thread, not the BA2018... 😀 😀 😀 need 24V rails...
Use this transformer -
AS-0520 - 50VA 20V Transformer - AnTek Products Corp
Use this transformer -
AS-0520 - 50VA 20V Transformer - AnTek Products Corp
20VAC will rectify into 28VDC, minus 1.4 from the diodes, giving 26.6VDC. This leaves more than a volt and a half for the regulators (which they need) and would work fine and nothing gets hot because there's not a bunch of voltage to throw away.
And anymore everybody's line voltage is higher than normal, which will give a little extra voltage off the transformer.
The AS-0524 would work nicely as well.
And anymore everybody's line voltage is higher than normal, which will give a little extra voltage off the transformer.
The AS-0524 would work nicely as well.
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say minimum 2V5 for reg
say -10% mains voltage down]
say 1V3 for diode drop
going backwards , that's 25+1V3+2V5+2V5=31V3
divide that with 1.41 , thats 22Vac
it really calls for 48Vct xformer
you don't want your PSU acting as alcoholic under the curfew
say -10% mains voltage down]
say 1V3 for diode drop
going backwards , that's 25+1V3+2V5+2V5=31V3
divide that with 1.41 , thats 22Vac
it really calls for 48Vct xformer
you don't want your PSU acting as alcoholic under the curfew
Cheers everybody.
I've got a transformer, 50va with dual 24v secondaries. I also have a super regulator PCB and a universal PSU PCB.
I've got a transformer, 50va with dual 24v secondaries. I also have a super regulator PCB and a universal PSU PCB.
The maker of mine says to go to a slightly higher AC input voltage than the DC output you want.