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The most advanced GainClone amp yet

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Thanks Peter - I too have been loving your LM3875 pcb. I built my first one using the standard component pack and was blown away.

The second amp i built is a bit over the top (in spec, not in build!): huge bank of panasonic fm (12000uF per rail) with 100uf black gate N on the amp pcb. I've also got a 0.1uf black gate NX right on each power supply pin. Cheap ebay stepped attenuator, alps source selector. Each of the 3 analogue inputs has different coupling caps (horses for courses, and i never need more than one line in so i have the choice). I've also got a monica 2 dac board inside the chassis with separate transformer, rectifier bridge and psu cap bank.

Anyway, your work really impresses me - thanks again :)
 
Originally posted by Peter Daniel
Just bend the pins, here's one example:

An externally hosted image should be here but it was not working when we last tested it.


Hi Peter,

Great work, as always.

A couple of questions:

1) When bending the chip pins back a la the Patek, how do you get the bolt through the chip to secure it to the heatsink? Seems that the board is in the way.

2) I have enough boards to make the bridged dual-mono version the the Gainclone. Any pointers on how to connect the two sides of the chip together to parallel them? I'm inspired by the dual-mono Patek that was favorably reviewed on 6moons.com.

I may also email you about ordering a couple of the AudioSector PS boards - I have the v.1 Chipamp boards from the initial PD/Brian GT group buy and would like to take advantage of the wider pin spacing of the AudioSector PS board in order place the 1000uF caps at that location.

Thanks,
KT
 
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Joined 2004
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source for toggle switches

Peter Daniel said:
The switching module is an add on and can be removed if not used.


Hi Peter, those look like Audio Research toggle switches, can you share where you got those from? I've been trying to get a replacement switch for months now and the local dealer want's alot of money for one. Are they the same ones?

Thanks,

Stephen
 
Member
Joined 2004
Paid Member
source for toggle switches

attachment.php


Hi Peter, those look like Audio Research toggle switches, can you share where you got those from? I've been trying to get a replacement switch for months now and the local dealer want's alot of money for one. Are they the same ones?

Thanks,

Stephen
 
KT said:
1) When bending the chip pins back a la the Patek, how do you get the bolt through the chip to secure it to the heatsink? Seems that the board is in the way.

2) I have enough boards to make the bridged dual-mono version the the Gainclone. Any pointers on how to connect the two sides of the chip together to parallel them? I'm inspired by the dual-mono Patek that was favorably reviewed on 6moons.com.


I install the chip first, then the board. To remove the chip, you need to remove the board. But only 5 pins need to be soldered.

The wiring diagram for bridged/parallel version of LM4780 chip was posted here: http://audiosector.com/lm4780 amp.pdf
Doing it with LM3875 is the same.

Srajan still uses those amps, here the link to a more recent review when they've been featured: http://6moons.com/audioreviews/esoteric4/trio_2.html

hero_room_md.jpg
 
So, in the case of the balanced, the grounds are not switched? I was thinking of something similar using the TOCOS 4PDT with a preamp with an input transformer. I'd like a two source selector. I'd put the input and ground of both SE channels on one side, and the positive and negative of the balanced source on the other side. Not quite sure what to do with the balanced ground connection though :)
 
attachment.php


Hi Peter, those look like Audio Research toggle switches, can you share where you got those from? I've been trying to get a replacement switch for months now and the local dealer want's alot of money for one. Are they the same ones?

Thanks,

Stephen



Beautiful apparatus and parts are always in demand.

Theese toggle switches are one of those beauties.
And ofcourse Peters amps. Still in buisness Peter?
 
I install the chip first, then the board. To remove the chip, you need to remove the board. But only 5 pins need to be soldered.

The wiring diagram for bridged/parallel version of LM4780 chip was posted here: http://audiosector.com/lm4780 amp.pdf
Doing it with LM3875 is the same.

Srajan still uses those amps, here the link to a more recent review when they've been featured: 6moons audio reviews: Esoteric P-03, D-03, G-0s

hero_room_md.jpg

There's just one thing I don't like in that picture: the placement of the giant window. The mere sight of it makes me cringe :(
 
wow

From the inside, I was really influenced by Connoisseur preamps layout ;)

The front end consists of S&B102 TVC mounted on rubber dampers into Mardone Burl side panels. A stepping motor coupled to higher grade Elma switch allows remote volume control. The transformers act as phase splitters as well, allowing either balanced or single ended inuts and feeding the amps with balanced signal only.

The amps are basically Pateks in bridged configuration with a usual bypass scheme. The heatsink is made of bronze. Not a best material heatwise, but sonically better than other alloys.
Looks amazing! Sure that it sounds the same like it looks ) Great work!
 
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