Experimenting with Chipamp.com Mono PCBs

[Tripmaster]

Originally posted by Puffin
Nope, I know nothing.

Wot so that I can ***p on you.

I've heard its supposed to bring good luck!

[Tripmaster]

I've been trying to decide which P2P to go for over the last couple of days, after having a chat with Barry I have decided to buy 4 Chipamp PCBs from Mad about Sound. Its going to provide a robust platform for experimentation....well at least the components are less likely to fall off!!

Nick, it sounds like you love your 4 channel amp. Do you think it worth trying out with these boards?

Richard

[Puffin]

[Tripmaster]

Pictures can speak thousand words, I can think of only one my feathered friend

[ClaveFremen]

Originally posted by Tripmaster
I really like sound of my current Chipamp dual mono but I find some of the higher frequency range can occasionally sound harsh.

Can anyone suggest a nice selection capacitors-boutique resistors they have found work well together?

Try different bypass caps or better no bypass caps

Swap FCs with FMs or better with some audio caps (Muse, Silmic, etc.)

I've had a similar experience:

PS decoupling caps in Gainclone

I'm still waiting to try again FMs after removing the MMK bypass but I'm confident that this time they'll sound better.

Or perhaps I hope so, since I've to use them in my MyRef (not enough space for Silmics or Muses...)

[Stuey]

In amongst this amplifier chat, what the heck are you pommie nutcases going on about?

Stuey

[sangram]

I've used the following:

Resistors (Rf/Ri):

Carbon film
Carbon comp
Metal film (garden variety)
Holco
PRP

Capacitors (Ci):

None
Panasonic FC
Panasonic FM
Black Gate HiQ NX
Nichicon KZ
Elna Silmic RFS

The combo that works best for me (and it will be different for you) is Black Gate for Ci, PRP at Rf, Holco at Ri. I don't use input caps, and ensure my sources have low offset. I can achieve <20mV offset, mostly 4-5mV this way. I also don't use a Zobel but depend on layout and short signal and feedback path. The feedback resistor is soldered directly on the pins, and in most cases components do not extend beyond their own lengths. I haven't (yet) killed a speaker this way or faced any overheating or oscillation - so I'm assuming I'm doing OK.

I tried omitting Ci many times but the compromises in the rest of the circuit to derive low offset was killing the sound or the source. In the end I decided for the Black Gates. The Muse KZ does not sound as good here as in series application, the Pana FC is acceptable in a pinch though it hardens the sound a bit. The BG Nx gives a nice warm tone to the sound. I wire my amps P2P, and in such a way that it is quick and painless to experiment with the Ci cap, which I think has profound effect on the sound quality. When I started on chipamps three years ago I thought it didn't matter, but it does.

The Rf resistor is also pretty important - the garden variety metal film resistors in India make the sound very brittle and grainy. Carbon comps are slightly better, but carbon film sound horrible. I think more than the intrinsic nature of the material, the resistor construction and material quality is subpar as carbon resistors cost much less than metal films. Wirewounds sound excellent, but they are physically too large for Rf.

Supply decoupling is also pretty critical. I use Panasonic FM 100uF mounted on the chip leads with a 100nF X7R cap soldered directly across the chip pins. Pretty radical difference from the small leaded caps I was using earlier. I am pretty happy with the combo I use now, even if it cost me a pretty packet.

[Nuuk]

Originally posted by Tripmaster
I've been trying to decide which P2P to go for over the last couple of days, after having a chat with Barry I have decided to buy 4 Chipamp PCBs from Mad about Sound. Its going to provide a robust platform for experimentation....well at least the components are less likely to fall off!!

Nick, it sounds like you love your 4 channel amp. Do you think it worth trying out with these boards?

Richard

P2P is construction without using a PCB!

4 channel amp with either P2P or PCB makes no difference!

Don't get so hung up on the tiniest details! The best GC is the one that Frank Sinatra would have sung about if he had built one!

[Tripmaster]

Originally posted by Nuuk


P2P is construction without using a PCB!

4 channel amp with either P2P or PCB makes no difference!

Don't get so hung up on the tiniest details! The best GC is the one that Frank Sinatra would have sung about if he had built one!

Hi Nick

I know what a P2P is but I should have made myself clearer. I decided to go down the PCB route because I thought the board would withstand several component changes, and also provide a stable platform for the parts.

I am not toooo obsessed with different parts but if there is an assortment of components that may help to tame some of the high frequency distortion then that’s what I’ll try.

Richard

[Tripmaster]

Sangram / Dario

Thanks for your input, I will give that some thought.

Richard