Commercial Gainclone kit- building instructions

[tiglitosa]

Thanx Peter

I think i will give it a try although its a weird deisng and gives me already lots of puzzles (that is happening when you leave you designer wife to make the plans for the box )


thank you

[northernsky]

Hi,

I just completed two monoblock amplifiers using the Audiosector premium kit and I am doing the preliminary tests before connecting them to a speaker. I just tested the rectifier boards. I have two transfomers 300VA 25VAC with dual secondaries.
One monoblock seems OK, but the other one has a strange behavior (for me at least, a genuine newbie). Indeed using my DMM I measure 22 DCV at both V- PG- and
V+ PG+ which seems correct, but, by mistake, I verified that simultaneously they also measure 47ACV again between V-PG-, V+PG+ (?)

I checked and checked again, always the same result. The other monoblock measures 0 ACV at both V- PG- and V+PG+.

Any idea on my mistakes?


Renato

[mattcalf]

Gah, I'm stuck between which option to get.
Premium vs. Classic.

I don't know if I can justify the extra US$36 (~AU$50) for 2 extra Panasonic caps, a better quality PCB and name brand resistors.

Any suggestions/justification for either?

[tiglitosa]

Originally posted by mattcalf
Gah, I'm stuck between which option to get.
Premium vs. Classic.

I don't know if I can justify the extra US$36 (~AU$50) for 2 extra Panasonic caps, a better quality PCB and name brand resistors.

Any suggestions/justification for either?

IMHO i think that this extra cost is well justified.
If you get lets say caddocks or other resistors that have 1% tolerance that means the original values the designer has calculate will be present.
THD will be what he predicted etc. So imagine as far as resistor goes to have 20% tolerance.
You thing that your output will be the same?
The same goes with the other components as far as tolerance and magnetic behavior and other factors.
Wouldn't be to tedious to unsolder the components later for better ones?

Anyways thats just an opinion ;-)
The conclusion is to be happy with your sound



Nick

[mattcalf]

Originally posted by tiglitosa



IMHO i think that this extra cost is well justified.
If you get lets say caddocks or other resistors that have 1% tolerance that means the original values the designer has calculate will be present.....
Anyways thats just an opinion ;-)
The conclusion is to be happy with your sound



Nick

That's what I was after, I'm of course still open to others opinions but I think you mightve just justified the extra cost.

Cheers.

[tiglitosa]

Of course,

if you are curious enough after buying the premium kit you will start changing components to test the result

So its up to you !!

Nick

[mattcalf]

I think I'll go the premium kit, and down the line when I have funds for some other types of amps (I have my eyes on a T-amp at this stage) I will compare and either sell the losing amp or build some more speakers for them to power.

[Peter Daniel]

Premium kit is just the premium resistors and chips sorted for low offset.

You can get Classic kit and just order 6 additional resistors to save on cost (4 x 22k Caddock and 2 x 620R Rikens). 220R resistors are not really needed, and you can place jumpers in their spots.

Resistors tolerance is not critical, as long as they are matched to each other (in both channels)

[mattcalf]

You can get Classic kit and just order 6 additional resistors to save on cost

That sounds like the option for me, I'll be in contact once I have my current project under control.

Thanks.

[northernsky]

Hi,

thanks to the help of this great thread finally I got my two monoblock amps with the audiosector premium kit working.

Everything went (almost) smooth, no hum, no bump when I switch off the amps.

I still need to build a passive pre, now I am just checking them connected to an ipod (headphone out connection so I can set volume).

I only get a bump when I switch on the ipod with the amps already on.

Thank to everybody here

Renato