3-way signal splitter - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

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

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 18th June 2013, 12:42 PM   #1
SashaV is offline SashaV  Canada
diyAudio Member
 
Join Date: Feb 2006
Location: Toronto
Default 3-way signal splitter

Can anyone suggest some sort of a buffer that would split the signal out of a channel on a preamp into 3 feeds that would go to 3 amps?
Using a simple 3-way splitter cable results in horrible sound degradation, something is clearly needed to take care of impedance.
Not necessarily DIY, commercially available stuff would actually be preferred.
Transformer based devices are out of question.
  Reply With Quote
Old 18th June 2013, 02:52 PM   #2
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
A bit more information might help. A decent low impedance source ought to be able to drive three amp inputs without too much trouble simply by paralleling them.
  Reply With Quote
Old 18th June 2013, 07:22 PM   #3
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by SashaV View Post
Can anyone suggest some sort of a buffer that would split the signal out of a channel on a preamp into 3 feeds that would go to 3 amps?
Using a simple 3-way splitter cable results in horrible sound degradation, something is clearly needed to take care of impedance.
Not necessarily DIY, commercially available stuff would actually be preferred.
Transformer based devices are out of question.
Not sure what level of performance you need. Lot's of choices, search "audio distribution amp" either on Amazon or Parts Express.
  Reply With Quote
Old 18th June 2013, 08:00 PM   #4
SashaV is offline SashaV  Canada
diyAudio Member
 
Join Date: Feb 2006
Location: Toronto
Source is Bryston BP-26 preamp, intent was to drive a pair of 3 channel Bryston 6B amps, thus the need to split the signal 3 way.
As mentioned, using simple cable splitter the performance degradation is tremendous.
Same kind of degradation is observed no matter what kind of source is used, for example I also tried a multichannel DAC with digital volume control, so I had a chance to compare one to one connection without signal splitting (one output from DAC to one input on amp) and one to 3 connection with cable splitter (one DAC output to 3 inputs) and again the performance determination was enormous.
So clearly a buffer is needed to maintain impedance, and I am looking at best possible solution that will not impart any signature of its own).
  Reply With Quote
Old 18th June 2013, 09:22 PM   #5
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
The preamp manual claims to be able to output up to 15V into any load of 600 ohms or greater. That should be fine, although it also admits that the circuit is discrete so perhaps not as low an output impedance as an op-amp circuit.

The 6B manual indicates an input impedance of 50k.

That should all be fine. Direct connection should preserve the signal with no problems. Perhaps your units are faulty?
  Reply With Quote
Old 18th June 2013, 11:21 PM   #6
diyAudio Member
 
Join Date: Mar 2013
Default buffer stage

Quote:
Originally Posted by SashaV View Post
Source is Bryston BP-26 preamp, intent was to drive a pair of 3 channel Bryston 6B amps, thus the need to split the signal 3 way.
As mentioned, using simple cable splitter the performance degradation is tremendous.
Same kind of degradation is observed no matter what kind of source is used, for example I also tried a multichannel DAC with digital volume control, so I had a chance to compare one to one connection without signal splitting (one output from DAC to one input on amp) and one to 3 connection with cable splitter (one DAC output to 3 inputs) and again the performance determination was enormous.
So clearly a buffer is needed to maintain impedance, and I am looking at best possible solution that will not impart any signature of its own).
IIU correctly you are wanting to split your left and right to drive three (each) amp inputs. If so the input impedance of the three 50k amp inputs in parallel works out to 16700 ohms. Even if you have extremely low output impedance from your preamp the frequency responce is going to be impacted. There are lots of choices, but the challenge is to get up to the performance level of your Bryston's.
I have used Kramer, CE labs, Audio Authority and RDL. You can check them all out at Markertek (no affiliation). I'd lean toward a Kramer or RDL product.

HTH
  Reply With Quote
Old 19th June 2013, 08:24 AM   #7
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
A preamp that claims to be able to drive 600 ohms should have no difficulty driving 16700 ohms! Unless, of course, that 16700 ohms is highly non-linear - but in that case driving just one amp would be a (smaller) problem.

The only effect on frequency response would be a reduction in bass, if the preamp output cap is too small. But then it would already be far too small to drive 600 ohms.

Tell us more about this 'simple 3-way splitter cable'?
  Reply With Quote
Old 19th June 2013, 11:36 AM   #8
SashaV is offline SashaV  Canada
diyAudio Member
 
Join Date: Feb 2006
Location: Toronto
3-way splitter cable is XLR to XLR cable, on one end of t cable I have single XLR connector that is plugged into preamp output, on the other end I have 3 XLR connectors that lead to amps inputs, pins are wired straight.
  Reply With Quote
Old 19th June 2013, 12:58 PM   #9
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Does the amp have an input transformer? If so, minor imbalances could result in the three parallel transformers upsetting each other. How long is the cable? How long is the part that splits into three?
  Reply With Quote
Old 19th June 2013, 03:19 PM   #10
SashaV is offline SashaV  Canada
diyAudio Member
 
Join Date: Feb 2006
Location: Toronto
Bryston does not use transformers on amps inputs.
The part that splits in 3 is very short, 5in or so, cables to amps are 10ft.
I think jjrenman is correct, frequency response is impacted, highs simply disappeared.
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
signal splitter matej8888 Digital Line Level 7 11th November 2011 07:29 PM
Audio Y Splitter Not Splitting Signal Properly jeffbruce Everything Else 8 28th September 2011 08:28 PM
signal splitter buffer hozone Analog Line Level 8 19th July 2010 11:14 AM
Audio signal splitter (for preamp) Krislarsen Analog Line Level 3 21st February 2006 12:25 PM
Creating a differential signal from a single-ended signal for bridged amps Peter Daniel Chip Amps 45 8th November 2004 12:47 PM


New To Site? Need Help?

All times are GMT. The time now is 07:37 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2