Tube Integrateds...why not a preout for subs.....

02-28-12: Marakanetz
Not necessary it would require to have an extra tube for each channel(buffer). Just like in conventional preamp with one main 'out' that can be disconnected from poweramp 'in' I don't see a necessity to have a buffer stage unless you'd like to have both preamp section connected to amp and another set of preamp outputs together.

Yes, it won't always be necessary to have a separate buffer stage, which is why I said "often." But if the output of the preamp section has to drive an external cable and component (such as a sub, which commonly have relatively low line-level input impedances), as well as the input to the power amp section of the integrated, and if that has to be done without compromising the integrity of the main signal path (into the power amp section of the integrated), not having a separate buffer stage would require a much lower output impedance from the preamp section than would otherwise be necessary.

So either way there may be a much more significant impact to the design than simply adding a couple of wires and connectors.

Regards,
-- Al

My Rogue audio Tempest II Magnum has active and passive pre outs.

Al,
Not necessary it would require to have an extra tube for each channel(buffer). Just like in conventional preamp with one main 'out' that can be disconnected from poweramp 'in' I don't see a necessity to have a buffer stage unless you'd like to have both preamp section connected to amp and another set of preamp outputs together.

I believe the ARC VSi60 has a subwoofer out.

I always wonder why tube integrated manufacturers do not provide a preout for the use of a sub.

I'd imagine that it is often because it would require an additional buffer stage (for each channel), to provide a reasonably low output impedance for the pre-outs, and to prevent the main signal path from being affected by what is connected to the pre-outs. Keep in mind that the impedance level at the output of a tube-based circuit stage is usually far higher than at the output of a solid state stage, resulting in greater sensitivity to loading.

That would generally require the addition of at least one dual-section tube and several passive components.

Regards,
-- Al

A point of the REL "high level" input (from the amp's speaker posts) is to use the tone of the amp itself (a good, although maybe not all that important idea). So I second the REL suggestions (I use one with a Jolida amp...works brilliantly). Also, I've been using Neutrik Speakon plugs for years and they're very cool, and should be used in more hifi gear...stuck an angled one on my REL so it can sit close to a wall without the dreaded "cable claustrophobia" issue (also use an AQ angled iec adapter for the ac cable).

I believe that the Grant Fidelity tube integrated has pre outs, but I hear you in general. I'd also suggest speaker level inputs, particularly RELs. This is their recommended connection and RELs integrate very nicely via their Speakon to speaker output connections.

Indeed + descent phono section preferably with 2 gain settings for MM/MC, tape loops and descent headphone jack.

A lot of good subs use a high level input that comes off the speaker binding posts, so maybe you don't need a dedicated sub output.

Many tube integrated amps have sub out.
Manley Stingray has them, I believe most Jolidas do.
I guess the question is what tube amps have you looked at that don't?

There are tube amps that provide a preout, including the Cary Sli-80, but that one may be a little above the price range used. I'm sure there are others.

An alternative is to get a sub with speaker level inputs. There are lots of those, including some relatively inexpensive ones, and that's the recommended connection for some high-end sub manufacturers like REL and HSU. I have a small Mirage S8 that costs around $350 new and works very well with its speaker-level inputs.