Thanks, I had a read over the guide earlier today and spotted the very same mistake, appreciate you mentioning it though as I have on occasion missed things just like that.
I thought you were just photographing the op-amp also for we see of the orientation
Salas, just read of the BC327-40 mod. How many should I buy to sort through? Datasheet suggests an average hfe of 400, max 630, making a need for around 500 hfe on the upper end of specs.
Also, I’ve searched and can’t find the answer but, if I drop the gain to 2, how do I do it (r6?) and will it compromise the sound of my unit, which I’ve been very happy with.
I’m building the Pass DIY VFet amp and will be running 99db drivers in a TQWT so the gain in the DCG3 may be too much.
You do it with choosing R6=499R. Or 2x1k in piggyback parallel if handier.
I know two people with 2X setting personally. One has 102dB horn speakers the other one has 82dB ribbon speakers. First one says 3X was a tad better although he had to cut on preamp gain. Second one says 2X is a tad better although he had to increase his power amp gain. Go figure.
Trust your own ears in the context of your own system. Tech answer is 2X uses 3.5dB more negative feedback than the 3X setting. Also, system noise is 3.5dB lower for 2X.
About BC327-40 get 20 pieces to choose from maybe. Not crucial to pick them absolutely same hfe. +/- 20 is fine. 400+ hfe level is still very good. Not mandatory to hit 500 or something.
Thanks, I had a read over the guide earlier today and spotted the very same mistake, appreciate you mentioning it though as I have on occasion missed things just like that.
Guides are well done. Thanks again for that.
Also had to read them several times to stickly follow the procedure, because builds are/were done over several days, weeks and even more.
Use two coaxial cables. Common their screens at the Select board's output GND pad only. Connect their other screen ends separately to each GND pad near to each DCG3 channel's signal input pad.
I suppose that the same has to be done for the headphone-jack (R+L+GND, 3 wires): common the screens at the headphone-jack only and connect the other screen ends separately to each GND pad near to each DCG3 channel's signal output (HP) pad
What are people using as a decent quality headphone socket ?
Alan
I use these with silver for 1/4 inch plugs.
Neutrik NJ3FP6C-P 1/4 Panel Mount with Plastic Shell - Black Metal Housing / Silver Contacts
Something similar to that:
for thick front plates.
This is if your handphones are equipped 3.5mm plug.
Got the model for 6.35mm plug.
(Headphone socket for thick front plate?)
(Headphone socket for thick front plate?)
Thanks everyone I like the Neutrik Socket so I have ordered one of these
NJ3FP6C | Neutrik
Thanks , also looks good, Switchcraft do something very similar so I have ordered one of them as well
152B | Switchcraft 6.35 mm Panel Mount Stereo Jack Jack Socket, 3Pole | RS Components
Alan
NJ3FP6C | Neutrik
I've used this one successfully in the past.
BKL Electronic Kreimendahl | Klinkeneinbaubuchse 6,3mm Stereo, Einlochmontage, langes Gewinde
Question is... will you find it in your area?
Thanks , also looks good, Switchcraft do something very similar so I have ordered one of them as well
152B | Switchcraft 6.35 mm Panel Mount Stereo Jack Jack Socket, 3Pole | RS Components
Alan
OK so here are the options for the front panel !
large push button On / Off switch or small ?
Large Neutric Headphone Jack or small Switchcraft one ?
My preference is for the large for both
The on / off switch and Headpnone socket will be mounted to the right and left of the selector switch and Vol control.
The small hole in the centre of the front panel will have a single red LED from the Pre amp board.
Either side of that there will be 3 green LEDs which will show which source is selected from the switch
IMG_3012 by Alan Towell, on Flickr
Alan
large push button On / Off switch or small ?
Large Neutric Headphone Jack or small Switchcraft one ?
My preference is for the large for both
The on / off switch and Headpnone socket will be mounted to the right and left of the selector switch and Vol control.
The small hole in the centre of the front panel will have a single red LED from the Pre amp board.
Either side of that there will be 3 green LEDs which will show which source is selected from the switch
IMG_3012 by Alan Towell, on Flickr
Alan
Progress so far all boards built up but no wiring yet
Just going to be using a 4 input selector for now that I already had built up
PS not sure about the transformer as they are only 25VA each, ? are they adequate ?
IMG_2996 by Alan Towell, on Flickr
Alan
Just going to be using a 4 input selector for now that I already had built up
PS not sure about the transformer as they are only 25VA each, ? are they adequate ?
IMG_2996 by Alan Towell, on Flickr
Alan
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