Tube amps with pass-thru?

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jk319

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I know a certain brand was mentioned here recently, and I cannot yet find it (didn't try TOO hard). Search items like "tube+amp+pass+thru" sure gets a lot of hits here! Especially since "Pass" amps are so popular too! haha

I do enjoy my present refurbed NAD multi-ch amp, but I am already window shopping for the future. A good 2-ch amp. For now, and for at least still a good amount of time, my Logans are still part of the HT setup.

Anyone have a list of tube amps (or even great SS amps), that have pass-thru capability while remaining off? For obvious reasons of convenience, and perhaps the "stupid-proofing" will be of some worth too. :p

Thank you very much, and forgive the ineptitude and/or forgetfullnes. :rolleyes:
 
I think you are actually referring to tube preamps with a home theater bypass. I'm not aware of any amps that have a pass-thru, but several quality preamps have a home theater bypass loop. I believe the one that was mentioned awhile back was an audio research preamp and I think Dave (twich54) made the comment, so maybe he will chime in here.
 
Balanced Audio Technology tube preamps and Audio Research preamps both feature ht bypass.
 
Ohhhh...... oops! :eek: :p

Thanks guys. Ok. I was about to pose another surely stupid question, but maybe I should consider how this would be all hooked up in my head first :confused: :rolleyes: . Great to hear that BAT has it as well, since my dealer carries them, and they sound awesome.

Thanks again Rich and alive. Have a good weekend!
 
Believe me, I am right there with you. I would love to have a quality tube amp or class-A solid state amp for two-channel listening and my Sunfire multichannel amp for home theater hooked to the same pair of Summits without having to switch out cable connections every time I switched between the two. Unfortunately, I have not figured out how to do that yet.

Having the home theater loop allows you to have a separate signal path for two-channel (tube preamp) vs. multichannel (HT processor), but the signal ultimately has to end up at the same amplifier to get to your main speakers. Anyone know of a high quality speaker-level switch?
 
Believe me, I am right there with you. I would love to have a quality tube amp or class-A solid state amp for two-channel listening and my Sunfire multichannel amp for home theater hooked to the same pair of Summits without having to switch out cable connections every time I switched between the two. Unfortunately, I have not figured out how to do that yet.

Having the home theater loop allows you to have a separate signal path for two-channel (tube preamp) vs. multichannel (HT processor), but the signal ultimately has to end up at the same amplifier to get to your main speakers. Anyone know of a high quality speaker-level switch?

Rich, I really don't think that's the right path to go down. I've never seen a "High Quality" speaker level switch, and it's just one more level of grain that could be added to the signal path. No sir - wouldn't go there at all.

So what I used to do when I had my HT setup, and will likely do again when my dedicated room is complete is have my HT processor feeding my BAT VK31-SE via a bypass (any of the inputs can be assigned as HT bypass in the BAT). The BAT then fed my standard two channel BAT VK-6200 amp driving the ReQuests. I also had the HT process (an Acurus ACT 3) also feeding an Acurus 3 channel amp for the center channel and surrounds. Thus you still have your high end 2 channel setup as well as your full Home Theater in one system.

Could also be accomplished with just one 5-7 channel amp, but just get a really good one. I'm partial to the BAT, but there are also some great high-end multichannel amps made by Plinius, Cary, Theta and Bryston.
 
Mitt,

Thanks, I appreciate your input and agree with your suggestions. But it still doesn't really solve my problem. What I want is to have a really high end amp for two channel (tube or solid state class A monoblocs) and a multichannel home theater amp hooked to the same speakers. I want the high end amp (and a high end preamp) for two-channel music listening, but I don't want to deal with the heat output or the hours of use on that amp for watching t.v. or movies.

Right now, I have the Meridian G68 hooked up to the Sunfire Cinema Grand feeding the Summits, Stage, and Clarities. It sounds great for movies and television, and pretty darn good for music. But not near as good for music as I know the Summits are capable of sounding. (Remember, I have C.J. tube gear as well as the Pass Labs X-350.5, so I know what they are capable of and I am not there yet.

The problem is the Pass Labs amp and the tube amps put out too much heat for this particular room, especially when the projector and other components are on. I can deal with this when it is just me listening to music, but when I have a few other people in the room to watch a movie, it is just too hot. So I am left with the problem of choosing between using an inferior (in my opinion) amp for two channel, having two completely different systems in the same room, or switching speaker cables back and forth when I switch between two-channel music and multichannel or video.

I agree with your assessment that a speaker-level switch is probably not the answer. I am just not sure what other options there are. If anyone has ideas, I would love to hear them.
 
Not all amps need to double as auxillary room heaters. :) McIntosh SS amps run very cool. You could add for the mains a pair of McIntosh MC501 monoblocs, or if you prefer, a MC402 or MC252 stero amp. Just use your Sunfire for center and surrounds. I'm going to do something very similar to my system by adding either a pair of 501s or, possibly, the new and not yet released 300 watt tube amp. I would then use my MC207 for center channel and surround duty only.
 
Not all amps need to double as auxillary room heaters. :) McIntosh SS amps run very cool. You could add for the mains a pair of McIntosh MC501 monoblocs, or if you prefer, a MC402 or MC252 stero amp. Just use your Sunfire for center and surrounds. I'm going to do something very similar to my system by adding either a pair of 501s or, possibly, the new and not yet released 300 watt tube amp. I would then use my MC207 for center channel and surround duty only.

Yes, pretty much what I was trying to say as well. I'd put my BAT VK-6200 up against most of the solid state amps out there, it's that good.

Another way to do it would be with one of the Plinius amps where you can switch between modes. Use class AB for home theater, and switch it into Class A for your critical listening.
 
Yes, pretty much what I was trying to say as well. I'd put my BAT VK-6200 up against most of the solid state amps out there, it's that good.

Another way to do it would be with one of the Plinius amps where you can switch between modes. Use class AB for home theater, and switch it into Class A for your critical listening.

Lots of ways to skin this cat, it's just how many $$$ you're willing to part with.
 
Lots of ways to skin this cat, it's just how many $$$ you're willing to part with.

Yes, I suppose that's true. I am just pretty picky about amps and preamps. I have heard very few solid state amps that I really love the sound of that aren't class A biased. The mac monoblocs are fine amps, but they aren't really the sound I am looking for.

And Tim, don't think I haven't considered the Plinius. I am strongly considering a pair of SA-103's. Dual balanced mono mode -- 400 watts of Class A power for music listening, and a switch to turn the heat off when watching movies. Sweet! I know it's overkill for the Summits, but man would it sound great!

I just wish Pass Labs would have added a bias switch like that to the XA-100.5 monoblocs that just came out. I think those amps would be perfect for my system, but again it is a lot of heat output for home theater viewing. I'll let you know what I decide. Now that I have my multichannel system pretty well down, it is time to finish the two-channel system. I will soon be deciding on a new digital source, tube preamp, and two-channel amplifier.
 
Yes, I suppose that's true. I am just pretty picky about amps and preamps. I have heard very few solid state amps that I really love the sound of that aren't class A biased. The mac monoblocs are fine amps, but they aren't really the sound I am looking for.

And Tim, don't think I haven't considered the Plinius. I am strongly considering a pair of SA-103's. Dual balanced mono mode -- 400 watts of Class A power for music listening, and a switch to turn the heat off when watching movies. Sweet! I know it's overkill for the Summits, but man would it sound great!

I just wish Pass Labs would have added a bias switch like that to the XA-100.5 monoblocs that just came out. I think those amps would be perfect for my system, but again it is a lot of heat output for home theater viewing. I'll let you know what I decide. Now that I have my multichannel system pretty well down, it is time to finish the two-channel system. I will soon be deciding on a new digital source, tube preamp, and two-channel amplifier.

Rich my friend!

I honestly think that dual 103s are not overkill although a bit excessive AND expensive (too rich for my blood)... but if you wanted to go a similar route and have the luxury (yes, I said it... luxury) of having the bias switch, there's always used 102s which match the 103 spec-for-spec. Just some food for thought.

Now, if you said Boulder.... THAT'S overkill!

LOL! :D

Joey
 
...
I agree with your assessment that a speaker-level switch is probably not the answer. I am just not sure what other options there are. If anyone has ideas, I would love to hear them.


I'm going to disagree on the issues with a switch. A low grade switch might get in the way, but a well specified and wired switch should do the job quite transparently.

As a little data point for everyone: Most ML's have a switch in the signal path anyway. The 'bass contour' or 'presence' switches on some models are in line with the signal. So your signal might already be going through a $1 SPST switch :eek:

Also, many amps feature an output relay that is held off by a control signal until the amp stabilizes, then lets the relay contacts fall back to default-on position. So there you have an active switch in the signal path.

A reasonable speaker switch could be built out of some heavy duty DPDT relays that default to one of the legs and are electronically switched to the other. This would even give you remote control of the speaker selection :D

I have plenty of experience with big relays, as I built up my power management rig around some fairly large 30 and 20amp relays. That 30 amp is a beast, weighs a couple pounds just for the relay. :cool:

Of course, a simple pair of mechanical DPDT switches of appropriate rating will also do the job ;)

I’m sure if we look around, someone has already made a quality speaker switch for sale. If not, there is always DIY.
 
Just for info, my Audio Research LS25MkII preamp features a HT throughpass switching facility. When I want to watch multichannel, at the flick of a switch my dedicated 2 channel rig becomes a full blown home theatre system. It's a great feature to have.

Now with my preamp, the HT facility only works with the preamplifier switched on. When it's switched off, nothing works. This may also apply to other quality preamplifiers.

Regarding having 2 different amplifiers hooked up to the same pair of speakers, I can't see why you can't do that - as long as you only have ONE amplifier switched on at a time. On the other hand I can't see why anyone would want to do that. As far as I'm concerned, if your 2 channel system is your preferred choice for music, this should also apply to movies. I am not prepared to accept substandard sound for anything - otherwise I might as well buy a Bose Lifestyle system and be done with it! :eek:
 
I honestly think that dual 103s are not overkill although a bit excessive AND expensive (too rich for my blood)... but if you wanted to go a similar route and have the luxury (yes, I said it... luxury) of having the bias switch, there's always used 102s which match the 103 spec-for-spec.

Thanks for the input, Joey. As a satisfied Plinius owner and comrade-in-arms audiophile, I respect your opinion. Then again, I know you are biased and would just love it if I defected from the Pass Labs camp over to the Plinius Pentad. :D I will keep mulling my options. The amp will probably be my last upgrade. The source and tube pre will come first.

I'm going to disagree on the issues with a switch. A low grade switch might get in the way, but a well specified and wired switch should do the job quite transparently.

...

I’m sure if we look around, someone has already made a quality speaker switch for sale. If not, there is always DIY.

I was hoping you might chime in on this topic. I would certainly be willing to try out a switch and decide for myself if it negatively impacted the sound. I just have not been able to find one designed specifically for the job (and I am not really much for DIY). If you run across a quality switch designed for this purpose, please let me know.

Regarding having 2 different amplifiers hooked up to the same pair of speakers, I can't see why you can't do that - as long as you only have ONE amplifier switched on at a time. On the other hand I can't see why anyone would want to do that. As far as I'm concerned, if your 2 channel system is your preferred choice for music, this should also apply to movies. I am not prepared to accept substandard sound for anything - otherwise I might as well buy a Bose Lifestyle system and be done with it!

I am a little leery about having two very expensive amplifiers hooked up to the same set of very expensive speakers at the same time. Sounds like a recipe for disaster.

As for why, I explained that in my earlier post. I prefer Class A solid state or tube amplification for music, but when I get several other bodies in the room for home theater and the projector is running (which puts off a fair amount of heat itself) it just gets uncomfortably warm. Also, if I am using a tube amp, I really don't want the hours on the tubes just for movies.

I have very different needs in sound quality for movies than I do for music. But please understand, we are not talking about "substandard" sound even for the movies. In case you didn't read my earlier post, I mentioned that I am running a Meridian G68 processor into a Sunfire Cinema Grand amplifier for movies. This is super high quality sound and is incredible for movies and damn good for music. But as I said, it is just not quite the level of quality that I require for critical listening to music. I find that I am completely satisfied with this setup for movies, but am not quite there when listening to music. Hence the need for a different amp for two channel, and the accompanying thermal issues if this same amp is used during movies. Thanks for your input on the AR pre. I am strongly considering them as my choice for two-channel pre.

I have to apologize to JK319 for completely hijacking this thread. I hope some of this discussion is useful to you.
 
...Also, if I am using a tube amp, I really don't want the hours on the tubes just for movies.

I have very different needs in sound quality for movies than I do for music... I find that I am completely satisfied with this setup for movies, but am not quite there when listening to music. Hence the need for a different amp for two channel, and the accompanying thermal issues if this same amp is used during movies....

I have to apologize to JK319 for completely hijacking this thread. I hope some of this discussion is useful to you.

On the contrary, thank you for keeping the thread alive! I am learning exactly what I wanted (well, actually stuff that I didn't know that I wanted to know too, hah). We are in the same boat. I also find that HT is so much less demanding than music playback.

Sometimes I wish I was as avid as Joey, smart as Jon, and inquisitive as you...:p

If what I am learning is correct, perhaps the most "stupid-proof" method is to simply unplug/replug the speaker wires manually (which I did consider slightly inconvenient, but no big deal I guess). Because, you never know about having two amps turned on at the same time through a switch... well, I guess that can be taken care of by removing the trigger plugs and making sure none of the remotes could accidentally turn it on, etc.
 
Sometimes I wish I was as avid as Joey, smart as Jon, and inquisitive as you...:p

Now that would be a hell of a combination!


If what I am learning is correct, perhaps the most "stupid-proof" method is to simply unplug/replug the speaker wires manually (which I did consider slightly inconvenient, but no big deal I guess).

What do you guys think about this switch:

Niles Audio SPK-1 Switch

It is the best I have found so far. Only about a hundred bucks, so might be worth a try just to see how well it works. It requires a 12 volt trigger, but I have that with the Meridian.
 
LOL to the earlier posts guys.. that would be some frankenstein audiophile you got there.... we also need some cash... so we may have to sprinkle in a little bit of Frank (from Germany) or Barbados to have the money to afford the Statements then we can call it a day. :)

Anyway, with regards to the switch... the one thing I'm concerned is signal degradation. If you're running multi-thousand $$$ amps, only to punish the signal by squeezing it through a switchbox... I dont know man.

I've never heard it, I've never used a switch box.

But I'm just not sure if that's the best alternative that we got.

I would almost say I'd rather get a second set of speaker wire and leave it unconnected by the Summits (running from the other amp) for a quick and easy switcharoo...

Joey
 
Anyway, with regards to the switch... the one thing I'm concerned is signal degradation. If you're running multi-thousand $$$ amps, only to punish the signal by squeezing it through a switchbox... I dont know man.

Yes, this was Tim's concern as well and it is a valid one. But the only way to really know is to try it and see if I can tell a difference using the box.


But I'm just not sure if that's the best alternative that we got.

I would almost say I'd rather get a second set of speaker wire and leave it unconnected by the Summits (running from the other amp) for a quick and easy switcharoo...

This was my first thought and it sounds good, but in practice . . . turning off the amp in use, getting up and going behind each speaker to switch out cable connections, turning on the other amp and letting it warm up each time I want to switch between video/multichannel and two-channel . . . sounds like a real pain in the ars.

I guess I could just buy a separate pair of Summits and hook one pair up to each system. The best of both worlds! :D
 
I guess I could just buy a separate pair of Summits and hook one pair up to each system. The best of both worlds! :D

Rich... I like you a lot... but we need to admit you to the psych ward.
 

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