You didn't do anything wrong. You seemed to be wondering how to improve it. These are three big changes to the amps sound. New cap size is easy. Resistor replacers take maybe a half hour and a new supply maybe an hour or so. Try the BrianGT Aleph power supply. Cheap board and great results.
CRC means caps followed by a small resistor followed by more caps.
CRC means caps followed by a small resistor followed by more caps.
i don't use input resistor at all, instead, i use BG NX 22uF/6.3V (i've tried shorting this input resistor, no difference compared to BG NX installed. so i just left them there).
your resistor replacer works as an input resistor with LDR as the medium, i take it? if it is so, going resistor-less should be better i think *just my 2 cents. please enlighten me if i'm wrong*
i still haven't put the BG STD 1000uF yet, i don't know how big of an improvement i could expect going from fc 1500uF to BG STD 1000uF
peter daniel, would you care to chime in?
your resistor replacer works as an input resistor with LDR as the medium, i take it? if it is so, going resistor-less should be better i think *just my 2 cents. please enlighten me if i'm wrong*
i still haven't put the BG STD 1000uF yet, i don't know how big of an improvement i could expect going from fc 1500uF to BG STD 1000uF
peter daniel, would you care to chime in?
I would bet no resistor would be better for sound but its a safety measure to have resistance there. However I cap in the signal is a safety issue I leave out for Sonics. I mean replace the big caps near the chip with 100uf. Not 1000 or 1500. See diyaudioprojects.com for support on my 100uf suggestion.
Hi,
maybe you read in some of the previous posts I am now happily listening to music by an Audiosector premium kit in a gainclone amp with single stereo input.
I am going to build an input selector. Attached you can find a drawing of the wiring I intend to use for the signal grounds (input and output).
Is this wiring correct or can I improve it in particular to reduce the risk of ground loops?
Thank you
Renato
maybe you read in some of the previous posts I am now happily listening to music by an Audiosector premium kit in a gainclone amp with single stereo input.
I am going to build an input selector. Attached you can find a drawing of the wiring I intend to use for the signal grounds (input and output).
Is this wiring correct or can I improve it in particular to reduce the risk of ground loops?
Thank you
Renato
Attachments
The choice of the parts in a kit has been very specific and when you start with substitutes, the tonal signature might become completely different.
I couldn't find any better resistors for a premium version than Caddocks and Rikens. Rikens are not available any longer and closest replacement is Kiwame, which sounds quite similar. You mentioning tantalums and IME those resistors were quite different (comparing to Rikens)
What size BG F cap are you using on amp board? If you want to get close to Patek, I would strongly suggest BG STD 1000uF in rectifier section and 100uF caps on the amp boards. I'm not sure about BG F here, as those are different than BG N I'm using myself, but Panasonics FC are pretty close in tonal signature to BG N's.
I understand that you are using BG NX 22uF/6.3V for input coupling. If you make sure that your sources do not produce any DC offset, you may omit that cap as well. I also don't use R1 resistor.
Thank you. It took more than one year to get the amp finished: I hope to be a little more fast with the input selector.
Renato
Your expectations depend on your reference and I do not know what is yours.
Concerning my amp, Audiosector premium kit with standard Panasonic caps, I am very satisfied and I found an incredible improvement in sound when compared with my commercial YBA Integrè integrated amp (respected in the audio magazine world and class A on Stereophile during 90s). Finally I got the transparent and natural sound from my Jordan JX92 drivers I heard at audio shows but never realized at my home. I did not realize how important was the amp for the final result.
A main difference between our amp is that, if I well understood, you are using 1 trafo 225VA while I am using a dual mono configuration with 2 trafos 160VA 25VAC.
The only limitation I clearly see of this chipamp is the possible lack of sufficient power in case of low speaker impedence and/or efficiency.
Renato
i think you misunderstood my previous post. the 1500uF panasonic fm are installed in the rectifier board (the one with 8 diodes). while for the 2 electrolytic caps in the amp board (left and right side of the LM3875 chip), i use 100uF/50V Blackgate F
thank you for your reply, peter
yes, i do have BG STD 1000UF as per your suggestion. but i haven't installed it yet, now it's still panasonic fc 1500uF sitting on the rectifier board
in the amp board, i use 100uF BG F since panasonic fc is a very mediocre caps in my opinion, so i went with the BG F (i have good experiences with BG F)
so you suggest me to use panasonic fc 100uF on the amp board, and BG STD 1000uF on the rectifier board?
regarding the fuse, will it bring any improvement if i change the 2A slow blow fuse to 3A?
how is it lack of power when even the amp itself draws less than 2A?
it was very hard to find riken gold 680R 0.5W at that time, only 560R & 3k3, so i went with audionote tantalum. i thought kiwame would be even worse than the tantalum
i'll try your recommendation on the BG STD first, leave the BG F in place, and see how it sounds. thanks!
will report back soon
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Have you ruled out your signal source? How does it sound with an another amp? The LM38xx is pretty good if you do it right.
Or his speakers? If the amp is set up properly, then it's another problem. Mine is awesome, but my hearing isn't that good anyway...
I am not the right person to give technical comments (I can just copy a project at most).
The LM3875 datasheet gives 3.16A peak output current at 40W and 8Ohm loads.
I could verify myself that, even if my chipamp outperforms (in my view) my commercial YBA amp, the YBA provides a much higher sound pressure level: it is rated similarly 50W at 8 Ohm (but 90W at 4Ohm).
Renato
i'm using my modded dacmagic. it sounds great with my other equipments
btw i'm using headphone, not speaker (very heavy to drive, like AKG K1000. i need to crank the volume od the GC to 1-2 o'clock to get to convenient listening level)
i changed the caps in rectifier board to BG STD now, it sounds much more open!! but the low bass quantity is still less than before. i guess i will just let it run for a while before making any further judgments
after changing the caps, i measured the dc offset on the output of both binding posts. it reads 90 & 94mV on the left and right channel respectively when i set the potentiometer to maximum. is this normal?
after changing the caps, i measured the dc offset on the output of both binding posts. it reads 90 & 94mV on the left and right channel respectively when i set the potentiometer to maximum. is this normal?
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That's not right I think. Those headphones have 120ohm impedance and 74dB/volt sensitivity. You should only need a couple of watts to drive them to full output.
What are you, the fact police? Why don't you look it up yourself?
Yeah, I made a little mistake, what do you care?
74dB/milliwatt. It makes 107dB with 1 watt input.
Are you happy now?
Please, just go away.