GainConcept No.5

[Stabist]

In last months I've been quite GainBuildingMan ...

This is the last of them for now - 5th in the row to be exact - each of them different - from the first with LM1875 (the only to be not so sucesfull), followed with LM3886 "Patek", then experimenting by OPA541/OPA2604 combination (which shows a lot of potential but it still needs a proper chassis), then one with LM1875/NE5532 combination - just to improve bad taste from first attempt - it suceded
- and recently a friend of mine supplied me with a pair of OPA541 and OPA627 and some other parts (2 trannies, chassis, etc) - so I decided to fiddle a bit - and so GainConcept No.5 was born

Not yet tested on my main speakers - but so far it sounds very promising ...

It has +/-30V on chip rails and total gain around 33, 10k log 12 step attenuator, etc ...

 

[Stabist]

interiour

 

[Stabist]

attenuator

 

[Stabist]

in action

 

[Stabist]

back

 

[jleaman]

Not yet tested on my main speakers - but so far it sounds very promising ...

NEVER EVER test your first powered up amplifier on your main speakers I always use a cheap or free driver : O ) and run it for several hours. Ive seen speakers on tested first build amps. They don't smell to well either.

 

[Stabist]

last one for now

 

[Stabist]

@jleaman - yep - as said - he doesn't deserve yet to get connected with main amin speakers - for first few hours he had to be satisfied with some old car units ...

Now it's feeding some old Samsung speakers ...

And in the morning - if everything OK - it will be tested on my main system ...

 

[DC Dave]

Nice looking chassis. What are the dimensions? Also any functional reason for two LEDs opposed to one? Let us know how it sounds.

 

[XELB]

It looks really nice good job



In my opinion you should not use in the output those thin cables.
I think there is no point in having thick speaker cables if the output in the amplifier doesn’t have nice cables(inside).
For testing you can use that ones but once you have finish the amp you should consider change the cables for something better.
It’s just my opinion and tip.


Ps: I use speaker cable. 2x1,5mm oxygen free for each “banana output”

 

[Stabist]

@DC Dave

chassis itself ain't something special - as a matter of fact - if this would be build for myself - the chassis would a bit more "serious" one - that is - build out of 10mm and 5mm thick Al plates ... But as said - it is build for a friend - and with parts he gave to me ...
The dimmensions are something like 220x230x55mm and 2mm thick plates
2 leds are there because the construction of the amp is two separated mono amps in same chassis ... so each indicates one channel ...

@XELB

thanks for your tips - but those cables are more than perfect for GainConcept Allready tested many cables with my other amps ... All my GCs are internally wired with CAT5 and similar thick (but silver) cables and they work well ...

PS: in my main sistem I use pure silver cables (0,35 and 0,5mm thick wires)

 

[tobias_svensk]

Looks nice!

Is it a chassi made from Frontpanelexpress/Schaeffer with their profiles?

 

[tobias_svensk]

Ok, 5&10mm... maybe not Schaeffer then

 

[carlosfm]

All my GCs are internally wired with CAT5 and similar (but silver) cables and they work well ...

But you shouldn't route unshielded signal wire near the trafos.

Btw, have you tried electrical solid core copper wire (1.5 or 2.5mm) for internal speaker wire on your amps?

 

[Stabist]

NO no no Tobias - this chassis is something like Fischer - supplied by some local manufacturer/seller (it just might be that he's something like "OEM" for Fischer Electronic) - and thickness of plates is something like 2mm ...

10mm and 5mm are "my standard DIY" chassises ... - like this that will eventually become AlephL for same friend of mine ...

 

[XELB]

thanks for your tips - but those cables are more than perfect for GainConcept Allready tested many cables with my other amps ... All my GCs are internally wired with CAT5 and similar (but silver) cables and they work well ...

PS: in my main sistem I use pure silver cables (0,35 and 0,5mm thick wires)

If you have tested, who am I to say something


I use Chord Carnival Silver Plus. It's a good and affordable cable, I recommend.

 

[Stabist]

Carlos - I know "I shouldn't" - but I tried - and no hum - so I won't change them for shielded ones ... Otherwise I would do it ...

Yep - I allready tried electrical cables ... Far long ago ....

As said - I'm quite satisfied with results I get with usual cat5 - or in "premium" version pure silver wires with 0.35mm and 0,5mm in diameter ...

 

[planet10]

Originally posted by XELB
I think there is no point in having thick speaker cables if the output in the amplifier doesn’t have nice cables(inside).

Which brings up the question as to whether thick speaker cable is worthwhile ...

dave

 

[XELB]

Which brings up the question as to whether thick speaker cable is worthwhile ...

dave

Not really
Bigger the Thick of the cable lower the resistor.
(and bigger the distance between the amp and the speakers, bigger the power you lose)

If you want to have the same output power with a thin cable, the thin cable must have better conductivity.
For example, the thin is made of silver and the thick is made of gold or aluminium.
(silver have better conductivity than gold or aluminium)


This is one of the reasons why thick and good conductivity gives you punchy bass.

 

[carlosfm]

This is one of the reasons why thick and good conductivity gives you punchy bass.

Punchy bass alone doesn't make a good sound.
Too much is too much, too little is too little.
There's a spot for everything.

And btw, the shorter the speaker cables, the better.