Commercial Gainclone kit- building instructions

[udailey]

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.

[idjoel2000]

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?

[udailey]

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.

[northernsky]

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

[udailey]

looks right

[Peter Daniel]

Originally Posted by idjoel2000

hi, i'm finally finished my premium gainclone (after 1 year+ of delay. lol). it is the premium version with caddock resistors, and audionote tantalum instead of riken gold. supply caps in amp module is BG F, and supply caps in PSU module is Panasonic FC 1500uF/35V (i have BG STD 1000uF/50V but decided to use the FC for testing). toroid is talema 2x25V/4.5A 225VA

it's been up and running for more than a week, easily more than 50 hours break in. i'm still not quite satisfied with this amp, as i think this amp sounds not as open as i want it to be (i have really high hope for this amp)

power ground has been well implemented in this gc (i followed peter daniel instructions very carefully and specifically)

i'm using 230V/2A slow blow fuse at the moment (SHIBA), will it sound better if i use 3A or 4A fuse instead of the current one?

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.

[northernsky]

Originally Posted by udailey

looks right

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

[northernsky]

Originally Posted by idjoel2000

it's been up and running for more than a week, easily more than 50 hours break in. i'm still not quite satisfied with this amp, as i think this amp sounds not as open as i want it to be (i have really high hope for this amp)

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

[idjoel2000]

Originally Posted by udailey

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.

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

Originally Posted by Peter Daniel

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 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?

[Peter Daniel]

I wouldn't expect any difference with fuses and yes, I would suggest to start with Kiwame for gain setting, BG STD 1000uF at rectifiers and Panasonic FC 100uF on amp board, and then experimenting with different components, if needed.