New adventures in A level audio

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Hi philpoole !

I am listening to gainclones for about 2-3 years and I have tried a lot of chips (LM3875, LM1875, OPA549, TDA2050 and TDA2030)and for my ears TDA2030 sounds the best (no regs, just 1000uF on pins, no input cap and no cap to ground on inverting input ). It has some kind of magic hard to describe. Bass is deep and powerfull, mids are sweet and hights are just the way I like it.
The second best is LM1875.
The best thing would be to build the setup with easy access and then swap ICs to hear the difference. I have a copper block on a piece of plywood for that purpose.
I hope I helped.
 
Hi Igla,

Good to hear your feedback. Thankyou.
At the moment, very slowly, I'm just recommissioning the other three.
They haven't exactly been stored correctly for the last decade, so they need a bot of attention to get them up and running again.
One module provides no output at all, so I suspect the chip output has been damaged, as all the voltages around the board seem reasonable. Thankfully, I did order a few TDA2030s for spare via my school (I wonder if they're so generous nowadays?).

Most importantly, I'm having fun!

I hope to get all four going and start running them in stereo and comparing to other amplifiers.

Cheers,
Phil
 
Chipamp madness!
Oh dear, you lot have been affected haven't you ;)

I'm not addicted (yet). I'm toying with a JLH class A next (but I need to save a LOT of pennies for the PSU - a definite advantage of the chip amp). Has anyone been able to compare a chip amp to something like a JLH (don't tell me, I'll have to go and build it myself :rolleyes: ).
Its unlikely to happen for a year or two, so I might try a p2p LM3886 or something instead.

Well, a couple of the boards were duff - which doesn't surprise me considering how bad my soldering was back then.
So, I will replace the chips on those two and try to resurrect them.
But, I do have two working boards!
It wasn't set up particularly well wrt speaker positioning, but it sounded quite respectable in stereo to be fair.
I still need to do a comparison to my normal setup, but its sounding good.

I don't know if you can see the heatsink in the original picture I posted, but its an extrusion with fins down each side. Its about 15mm high, 45mm wide and maybe 80mm long. I have both amps attached to this heatsink, and it doesn't seem to be getting warm, so I am assuming its big enough?

Cheers,
Phil
 
I'm not moving on, I'm just trying everything. And, chip amps are the only way I'll ever be able to bi amp.

Yes, I suspect some form of buffering should improve things. Also, I'm going to try some extra PSU decoupling capacitance closer to the chips (there's currently 100uF per rail per module, and 16,000uF in the PSU about a metre away). An extra 1000uF per rail per module should help, or be good practice at least.

Cheers,
Phil
 
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