universal chip pre-amp project

[digi01]

the sch file of test PSU.

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Zang

[tent]

wow, really simple indeed, and I like it!
actually I've to say that I really like the "simple" way.. one can always start from simple and improve later on step by step but only if needed and if there are really imporvements..

tent:wq

[tent]

On the abowe PSU con you give some more info on those DW diodes?

Ok, buy coming back to the UCPv1smt: I've seen you used as CAPs all 47uF ones instead of the 1uF ones, is there some particular sonic reason? (also the 200p cap is a 330 one.. )
Just curious you already where finding out something particular.

tent:wq

[40 watt]

Letter from China came today...very nice!!!

That was fast. I've waited longer for stuff from the U.S. Digi soldered the resistors on one board for me and the other I'd like to solder these mini resistors myself, for experience. Thank you Digi! This will be a wonderful project and a great match for feeding my LM4780.

[digi01]

the test preamp is completed.
because it is designed for universal,i do a overall test with some opamps.opa2134,opa2604,ad8620,ad8397,ad823,lm6172, ne5532(big S),sa5532,ne5532(ti),opa2227,opa2111,ad827,lm4562.
i prefer detail & nature sound,i think lm4562 and opa2227 is better.

to tent:
the DW diodes is 1n5242.the 500mW power dissipation is ok for ucp module load.
i have some 47uf caps in stock,so i use them.
what you mean the 330 one?the orange cap is input cap Ci.i use 0.33uf philips.
I use single copper cable for sginal route.
the volume pot is before the ucp module.

--
Zang

[tent]

Originally posted by digi01
the test preamp is completed.
because it is designed for universal,i do a overall test with some opamps.opa2134,opa2604,ad8620,ad8397,ad823,lm6172, ne5532(big S),sa5532,ne5532(ti),opa2227,opa2111,ad827,lm4562.
i prefer detail & nature sound,i think lm4562 and opa2227 is better.

to tent:
the DW diodes is 1n5242.the 500mW power dissipation is ok for ucp module load.
i have some 47uf caps in stock,so i use them.
what you mean the 330 one?the orange cap is input cap Ci.i use 0.33uf philips.
I use single copper cable for sginal route.
the volume pot is before the ucp module.

--
Zang

Hi Zang,
the letter arrived to me yesterday afternoon too! Great!
I'll try and start my tests by today..
Ok for the caps, I have 10uF and also 47uF available, In this case do you have suggestions which is better?
And ok also for that 0.33uF from philips.
For the diode, since I only have a very big toroid trafo (250VA) available at the moment I was thinking to put a very big diode bridge (something like 35Amps so I do not blow them with inrush current..), do you think this could influence sonic performance?
And I looked at you picture up there: really nice! But what is that PSU you have there? Lot of caps.. and why is there only a couple of cables coming from the trafo to the psu? (yellow ones)

Thanks and let you know,
tent:wq

[digi01]

to 40 watt,tent,thanks for the news.

for the caps,i prefer small size & big capacitance.if the 47uf is as small as 10uf then use 47uf.
for the input caps Ci,0.33uf,0.47uf,1uf is ok.if the bipolar power supply is great matched then the Ci can be bypassed.
for the diodes,i have not experience to use such poweri think 1n4007 is all right for this project.
the transformer in my test only have single secondary coil,AC 10V 1A.i use half wave rectifier.
i have lots of 470uf/25v caps in stock.it is industry degree and i like its size.i connected them in parallel 8*470uf+8*470uf for the psu.

--
Zang

[tent]

Ok, thanks for the opinions!
But still do the size of the capacitance not influence the sound? 4.7uF 10uF and 47uF should not sound the same (an also if they would be made of mylar instead of being electolythics would do difference.. or not so much in this application? Because if so maybe a 4.7uF non electrolythic would be better than a 10uF electro..uhm..
For the PSU I also have loads of 470uFs so I'll do the same..

Thanks,
tent:wq

[digi01]

Originally posted by tent
But still do the size of the capacitance not influence the sound? 4.7uF 10uF and 47uF should not sound the same (an also if they would be made of mylar instead of being electolythics would do difference.. or not so much in this application? Because if so maybe a 4.7uF non electrolythic would be better than a 10uF electro..uhm..
tent:wq

in the UCPv1smt PCB,the C1,C2,C3,C4 near the opamp is used to power supply filter.they value and quality will influence the high quality sound.
if a electrolyte capacitor having a small size,a high capacitance,a low ESR and an excellent LC value,it would be great.i think 1 to 10uf is a balance value.47uf is ok.100uf is too big.


good luck,
Zang

[tent]

ok, then I'll use some non eletrolythic 4.7uF I have around for C1-C4..
for Ci I'm also in doubt if using a couple of 0.300uF(300nF) non electrolithic or better a couple of 4M7 or even a couple of 1M5.. suggestions?

besides that I completed the PSU now.. using some 16 of those 470uF elettrolyths, connecting a 12V toroid, what I get on the output is 14.2V DC.. isn't this too much? isn't this going to damage the LM4562?

almost ready for testing..

tent:wq