Salas DCG3 preamp (line & headphone)

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OK i try to tell a little about The loudspeaker

it plays very dynamic with ,what i will call big sound,,voices are really good,,easy to hear what they sing...acoustics guitar sound really live and with great dynamic ,,more realistisk than ordinary dome tweeter..
the bas from those 18" is just totally under control,,,it is super to hear drums and bas
guitar
i plays normally concert dvd,,,and sit and listen to well recorded dvd is just marveles

give the feeling that you are there,,,loud and clear,,,

for me it is the best speaker i have used

i have tried many different diy speaker,,,with scanspeak audiotechnology,,peerles and so on
the last speaker i have was gr research ls9 line array (they was also great but not op to The Loudspeaker)

sorry i am not so good in english,,hope you understand a little about it

best bjarne

High sensitivity and controlled directivity sonic hallmarks... You got the prototype loudspeaker from Troels or you made your own copy already?
 
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Salas

i can not find the tread where you show some Socket to use with the bc237-40

have you a nummer on those socket...

i will try them again ,,,because i have change speaker and dac

use now Troels Gravesen The Loudspeaker--- and dac from Mirand audio

Best Bjarne

Here is the one I will be providing with optional kits for BC327-40 in the next GB.
Of course anyone who has existing boards can purchased 4 of these with matched quad of BC327-40.
Mouser part : 535-03-0518-10
03-0518-10 Aries Electronics | Mouser

I am not a fan of cutting those pieces into smaller units.
 
A good quality i.c socket is a source for transistor sockets.;)
 

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diyAudio Chief Moderator
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Not to forget mentioning, the DCG3 boards from now on will be marked V1.03. I found the time to do little things, and I asked CRT to retouch on it, like I thought of a way to have the relay's resting position at GND and not at NC (no connection) but not to be shorting the output either, broke the ground lane in two channels and put bridge pads underneath so your grounding scheme in builds can be fully flexible, there is J3 printed for the BF256 on the board too as in the schematic now, not Q5. Performance wise nothing changes, just little perfectionist touches on the board's practicality.
 

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Did I just kill a channel?

I powered up one side of the DCG3 using dual mono Ultra BiB. The output voltage measured 16V8 after the diodes came on and the relay clicked.

I also fiddled on the VR1 but there wasn't any effect.

I only realized that the BOM called for plastic TO-220 grommets when I was checking for digital continuity on the stainless steel mounting screws of the MOSFETs. I did use the SIL-pads between the chassis heatsink though.

I measured the resistance between the MOSFET legs of M1, M2 and M3 with the un-powered channel, they seem to match.

The weird thing is I had done the same mounting for the MOSFETs of the UBiB and it didn't complain / smoke.

Did I kill the baby?
 
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Mosfets metal tabs should not show electrical continuity to the chassis. The Ubib's current limiting function can protect for over-current damages. You should power both channels, because the op-amp feeds from the left side PSU while the relay circuit feeds from the right side PSU. A healthy working Mosfet should show few Volts VGS (DC voltage between its left and right legs).
 
What is the recommended fuse for the dual mono 230V 80VA line DCG3?

I used a 600mA fuse earlier and that blew after I flipped the DCG3 over to drill and attach the feet for the chassis. Not that I drilled into the PCB but likely that the components moved.

I will disconnect the DCG3 from the UBiB v1.3 to investigate after I get a fuse replacement.