Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Salas DCG3 preamp (line & headphone)
Salas DCG3 preamp (line & headphone)
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 14th September 2017, 05:41 AM   #2121
r_jik45 is offline r_jik45  Japan
diyAudio Member
 
Join Date: May 2005
Location: Jpn, Fr
Salas,

First of all thanks for sharing... I'm on the way to sign-up for the GB.

I've read the whole 212 pages of the thread and I don't seem to find again the info regarding the DC input for the I-Select board. Not sure if it was here or in another thread...
What can be removed from the I-select board if a DC is already available? Just the diodes?
+/- 17-18V should be available from the preamp power supply. But, in case, what could be the minimum input DC?

Thanks again!
  Reply With Quote
Old 14th September 2017, 06:45 AM   #2122
bambadoo is offline bambadoo  Norway
diyAudio Member
 
Join Date: Feb 2003
Location: West Coast of Norway
I have done it like this. Works like a charm
Attached Images
File Type: jpg 20170914_084252.jpg (930.0 KB, 449 views)
  Reply With Quote
Old 14th September 2017, 07:04 AM   #2123
r_jik45 is offline r_jik45  Japan
diyAudio Member
 
Join Date: May 2005
Location: Jpn, Fr
bambadoo,
Thanks. Yes, AC to AC Will save the pic anyway in case.
But still wondering about the DC bypass

By the way, why did you skip the 1st relay for the input (right hand side)?
  Reply With Quote
Old 14th September 2017, 07:11 AM   #2124
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Salas DCG3 preamp (line & headphone)
Quote:
Originally Posted by r_jik45 View Post
Salas,

First of all thanks for sharing... I'm on the way to sign-up for the GB.

I've read the whole 212 pages of the thread and I don't seem to find again the info regarding the DC input for the I-Select board. Not sure if it was here or in another thread...
What can be removed from the I-select board if a DC is already available? Just the diodes?
+/- 17-18V should be available from the preamp power supply. But, in case, what could be the minimum input DC?

Thanks again!
Hello, you are welcome.

Its an input select accessory for any preamp, has a short thread in the GB section with a pdf guide and few clarification answers also. It was introduced separately and wasn't further analyzed here while not being a dedicated part of this preamp.

Some fully populate it for its own PSU and tap from one AC secondary at the DCSTB transformer input connector to power it via its AC input connector. Few even give it a small trafo of its own. Others skip its bridge diodes and populate the rest but with a smaller filter cap like 100uF for local DC bypass and tap raw DC or regulated output DC from DCSTB to power it via its DC input connector.

Read the guide and post #31 in its thread there: GB For Salas I-Select Mesmerize Type input selector and volume control
  Reply With Quote
Old 14th September 2017, 07:14 AM   #2125
bambadoo is offline bambadoo  Norway
diyAudio Member
 
Join Date: Feb 2003
Location: West Coast of Norway
Quote:
Originally Posted by r_jik45 View Post
bambadoo,
Thanks. Yes, AC to AC Will save the pic anyway in case.
But still wondering about the DC bypass

By the way, why did you skip the 1st relay for the input (right hand side)?
Because of fitment, symmetri and all that And needed only 4 inputs. (well in practice only 1 input) Still I have the option for one more input. Drilled holes in the case.
Also I bought 2 i-select boards and only have 10 relays at hand so I thought total 5 relays each board.

Was also thinking av DC input but could not make it "fit" as good as this way.

Last edited by bambadoo; 14th September 2017 at 07:19 AM.
  Reply With Quote
Old 14th September 2017, 07:21 AM   #2126
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Salas DCG3 preamp (line & headphone)
Quote:
Originally Posted by bambadoo View Post
I have done it like this. Works like a charm
Yep, that's a clear picture example of the 1st case described in my previous answer. Fully PSU populated IN_Selector board with AC tapping from a channel's main transformer one 18V secondary. Thanks.
  Reply With Quote
Old 14th September 2017, 07:24 AM   #2127
r_jik45 is offline r_jik45  Japan
diyAudio Member
 
Join Date: May 2005
Location: Jpn, Fr
@ Salas,
Ok, thanks. So basically remove the diodes and change the filter cap to 100uF... Got it.
Can be used for this selector and I suppose more generaly for units with an AC input when a DC supply is available.

@bambadoo,
Aesthetics!
  Reply With Quote
Old 18th September 2017, 06:17 PM   #2128
RCruz is online now RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Salas DCG3 preamp (line & headphone)
Hi Salas

I would like to use a second relay to switch between outputs (Line / Headphones)

As to not complicate matters I would like to use the existing circuit that powers the delay relay and use a switch to activate a second relay.

I am not sure if the current draw from both relays can be supported by the leds.

I am also not sure if the circuit I am planning to use should work... please advise.
Attached Images
File Type: png HP relay.PNG (14.6 KB, 299 views)
Attached Files
File Type: asc DCG3 relay Headphone relay.asc (3.1 KB, 8 views)
__________________
RC
  Reply With Quote
Old 18th September 2017, 08:13 PM   #2129
RCruz is online now RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Salas DCG3 preamp (line & headphone)
A resistor from base to gnd improves things a bit...

Still I do not fully understand the function of the zeners....
Attached Images
File Type: png HP relay evo.PNG (19.2 KB, 244 views)
__________________
RC
  Reply With Quote
Old 18th September 2017, 08:36 PM   #2130
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Salas DCG3 preamp (line & headphone)
If also you need to have both relays engaged the Leds can reliably support up to their own nominal current (check the spec sheet of the ones you got vs your two relays needs). But usually its one or the other, not line output to amp and speakers playing while listening to headphones.

You don't need to double up on drive circuits. R1 C1 could be common timing delay and you could pull the relays through Q1 using a switch for which one's coil you prefer to engage. A two way for phones/speakers or a three way switch for phones/speakers/both if you must.

The Zener is to create a threshold voltage for Q1's base to open at as the RC is reaching it charging up.
  Reply With Quote

Reply


Salas DCG3 preamp (line & headphone)Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: Pass VFET 2 essential+supplemental kit and Salas DCG3 kit 32y0 Swap Meet 3 16th April 2018 05:22 AM
FS : Salas DCG3 pinnocchio Swap Meet 2 9th January 2018 10:32 PM
FS: 2x Salas DCG3 and DCSTB complete kits bvtrinh Swap Meet 5 26th October 2017 11:29 PM
WTB Salas DCG3 pcb or kit savvas Swap Meet 0 8th February 2017 10:50 AM
Using a line preamp to drive headphone ginetto61 Solid State 25 6th May 2015 06:19 PM


New To Site? Need Help?

All times are GMT. The time now is 12:07 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki