Looking for switch for two preamps into one amp

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bFletch

Member
Joined
Apr 6, 2020
Messages
42
Location
Little River, CA
I just got an Exasound E38 Mark II (and love it) and want to use it direct into my amp. But I have several other things using my preamp that will still need to get to the amp too. So I need to find a switch that will send either the exasound 6 outputs or the Marantz 7005 6 outputs to my Outlaw amp inputs. Does anyone know of a good solution for this? It's important that no filtering, volume or coloration happens. Just switching. Thanks!
 
Thanks, Kal, for the reply. Trying three different browsers I was not able to get through to your attached link. It is Saturday night so maybe the web trail there is just too busy. I tried and did get to Stereophile.com but searching their site for "Music in the Round" brought up 152 pages. I searched for a while but decided to wait. I can try again tomorrow morning unless you know of another way to the article.
 
Since I only have 12" to 18" distances to run for the music server side, I'm thinking I"d be happy with either one.
For single-ended, the best option is to find a used Zektor switch with the necessary number of channels and i/o options.
Best: Zektor MAS 7.1 (and you can't have mine)
Otherwise MAS3 does only 6 channels but:
1. you can stack 2 6channel switches from Zektor.
2. you can stack 2 4channel switches for other sources. Browse on AliExpress or Amazon for such.
 
Hi everyone,
I have different but related problem: I have 2 amps one a beautiful analog Sansui QRX 6001 and the other a great digital 7.1 Pioneer VSX-920-K: the 1st I use with my beloved turntable and quad vinyls and other inputs like a tape deck and Sony 850PS DAV video8 deck (for music only).
The digital amp I use with my Pioneer 440 blu-ray deck for blu-ray audio, SACD, and DVD-A discs as well as the tons of quad & multi channel files I have on hard disks.... I only use 4 channels as I am not mad on intrusive subwoofer bass and rarely listen to TV through my Pioneer amp (except music programs) so don't need the center channel either
My problem is I only have 4 speakers and no room to put any additional ones in my small home so I look for a switcher that would let me input the 4 channels of both my amps and select between one of them to power the speakers. I couldn't find anything on the net even after extensive search, does any one know where to buy one or clues on how to solve the problem? (I don't see any except build one which I am totally incapable of doing)
 
Are you talking about speaker circuits or line-level signals?

If you are switching speaker circuits, you need a way of loading the amp that is not driving speakers at the moment. I have seen several different amps (including a Sansui) self-destruct when operated while unloaded.

I once saw a Dynaco Stereo-120 amp destroy itself because only one channel was being used (and loaded).

I did this one time using a 4-pole-double-throw switch to select a speaker for one amp while using a load resistor for the other. You would need 4 of these.

If one of them has a discrete input, the line out of the other one can feed it. But you need to load the other power amp.

For line-level, it is easier. One 4-pole-double-throw or two double-pole-double throw switches can do the job. No load is needed on the unused output.
 
If you are switching speaker circuits, you need a way of loading the amp that is not driving speakers at the moment. I have seen several different amps (including a Sansui) self-destruct when operated while unloaded.
Really? They must have been very badly designed or have been valve amps. Can't think of a transistor power amp output topology that would care.
 
Are you talking about speaker circuits or line-level signals?

If you are switching speaker circuits, you need a way of loading the amp that is not driving speakers at the moment. I have seen several different amps (including a Sansui) self-destruct when operated while unloaded.

I once saw a Dynaco Stereo-120 amp destroy itself because only one channel was being used (and loaded).

I did this one time using a 4-pole-double-throw switch to select a speaker for one amp while using a load resistor for the other. You would need 4 of these.

If one of them has a discrete input, the line out of the other one can feed it. But you need to load the other power amp.

For line-level, it is easier. One 4-pole-double-throw or two double-pole-double throw switches can do the job. No load is needed on the unused output.

Thanks MidiMagic,
I assume this is a reply to my enquiry, I am not so sure I understand your explanations all I am looking for is a device in which I can plug the 4 speakers outputs of both my amps seperatly and switch BETWEEN the amps according to which one I use as a source and by so doing not having to unplug/replug the speaker wires from one amp to the other every time I use an analog source through the Sansui or a digital one through the Pioneer (unfortunately the Pioneer VSX-920 doesn't have analog pre-amp outs, which would solve the problem) perhaps I should change digital amp, any suggestion of a good one? as many of the more recent reasonably priced ones don't have multi channel analog ins or outs,
the previous digital amp I owned did (unfortunately it clapped out a short while ago after 20 years of good & loyal service)
 
I just got an Exasound E38 Mark II (and love it) and want to use it direct into my amp. But I have several other things using my preamp that will still need to get to the amp too. So I need to find a switch that will send either the exasound 6 outputs or the Marantz 7005 6 outputs to my Outlaw amp inputs. Does anyone know of a good solution for this? It's important that no filtering, volume or coloration happens. Just switching. Thanks!

This "thing" is out there that will switch 6 outputs. I don't know how good it is, i.e. any coloration or noise:

https://www.aliexpress.com/item/32879254344.html
 
Really? They must have been very badly designed or have been valve amps. Can't think of a transistor power amp output topology that would care.

As an audio service tech, I certainly saw many transistor amps that had blown out their output transistors because someone unplugged a speaker to silence it. It was one of the most common repairs I did. Without the load, the early transistor driver circuits could cause both transistors in a push-pull arrangement to momentarily turn on full at the same time, causing them to burn out,

Heathkit even put lightbulbs in the output transistor circuits of one amp to protect the transistors.

After a while (circa 1974), they learned to add snubber circuits to the drivers to prevent this.

Shorting the output usually caused catastrophic results too.

I have never seen a tube amp do that. Usually the tube or the output transformer overheated.

I even invented a word to describe what I smelled every time I worked on an amp that had blown its output transistors: "Smelk" was a rather acrid smell inside the case where the transistor blew. (But blown rectifiers smelled the same.)
 
As an audio service tech, I certainly saw many transistor amps that had blown out their output transistors because someone unplugged a speaker to silence it. It was one of the most common repairs I did. Without the load, the early transistor driver circuits could cause both transistors in a push-pull arrangement to momentarily turn on full at the same time, causing the transistors to burn out,

Heathkit even put lightbulbs in the output transistor circuits of one amp to protect the transistors.

After a while (circa 1974), they learned to add snubber circuits to the drivers to prevent this.

They put fuses in the transistor circuits to prevent this. But the transistors often protected the fuses by blowing out first.

Shorting the output usually caused catastrophic results too.

I have never seen a tube amp do that. Usually the tube or the output transformer overheated.

I even invented a word to describe what I smelled every time I worked on an amp that had blown its output transistors: "Smelk" was a rather acrid smell inside the case where the transistor blew. (But blown rectifiers smelled the same.)
 
Many transistor amps hate both.

For the original question, Google "audio source selector". I have several in my setup.
 
It helps to have been repairing amplifiers in a university town. I saw plenty of them.

It usually happened when one channel was being used for a mono signal (e.g. a PA) while the other channel was disconnected. The disconnected channel failed.
 
I guess if was that common a problem most manufacturers must put lots of warning notices on the rear panels and in the handbooks that these units must not ever be operated without a speaker connected. Strangely I've never seen such a warning.
 
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