How to hook up a preamp to a Integrated amp

After looking online, it appears there are different versions of the integrated amp. 1) Has no main amp input and using another preamp is not possible. 2) Has main amp input with toggle switch. 3) Has main amp input with jumpers to output. Which version do you have?

tsl49
Thanks for the info . Mine has no main in . Thought it seemed impossible from looking at mine . Shoot ! Just got the Int. a couple days ago and like but seems closed in compared to a Sim Audio p5 /krell ksa 100 combo .

And you are welcome, glad to help.

You could connect the preamp to one of the integrated's line-level inputs.  While that would amount to having two preamps in series, and from a philosophical standpoint keeping the signal path as simple as possible is usually to be preferred, that arrangement would certainly function properly, and very conceivably could provide fine sonics.

In doing that, the volume level would of course be affected by the controls on both units.  Just be sure to avoid turning up the P5's control far enough to overload the LSA, which I see has an input overload point specified as greater than or equal to 2 volts.

Regards,
-- Al
 

almarg , Thanks for taking the time to add to this post . So are you saying the most important thing is to keep the simaudio volume as low as possible ? In the past i had a similar situation with using a passive volume pot into a Primaluna integrated . In that situation i maxed out the volume on the Primaluna and used the volume pot for changing level . 

The P-5 has a moderate specified gain of 12 db balanced and 9 db single-ended. Those would be the gains it would provide with its volume control at max, and those numbers correspond to an output voltage that is about 4 times as great as the input voltage for the balanced case, and about 2.8 times as great for the single-ended case.

Most digital sources provide maximum outputs in the area of 2 to 3 volts single-ended, and twice that balanced. It isn’t clear whether the LSA’s "greater than or equal to 2 volt" specified overload point applies to its single-ended inputs or its balanced input or both. So to be certain that an overload condition won’t arise let’s say that the P-5’s volume control should be set no higher than what would cause a 6 volt input to result in a 2 volt output. That corresponds to an overall gain of -9.5 db. To be completely safe under all conditions you would therefore want to set the volume control to provide an attenuation of 9.5 + 12 = 21.5 db, or more.

Roughly speaking, rotary volume controls will typically provide that amount of attenuation in the area of the 12 o’clock position.

If you are using a vinyl source, or if your interconnections are single-ended, you could probably go somewhat higher than that position. And given the conservative assumptions I stated above, perhaps you could do that for many digital sources as well.

Overloading of the LSA’s input would result in obvious distortion, btw. While if you go too low on the P-5’s volume control, noise levels and/or sonics might be compromised to some degree. But I would expect that there would be a fairly wide range of settings of the P-5’s volume control within which the exact setting would not be particularly critical.

Good luck. Regards,
-- Al

To try the P5 with the LSA turn the LSA's volume pot to 100% max (effectively removing the pot from the circuit).

Connect via line inputs as previously mentioned.

I would also try running the LSA solo for awhile to see if the sound opens up/improves.

Onother option (after running the LSA for a week, or so) would be to test and possibly replace/upgrade the preamp section tubes.

The sound of various 6922 tubes is all over the map, from my experience, using them as input and/or preamp tubes.

I rolled NOS Amperex 7308's into my Statement's pre-amp section with huge results from the stock 6922's.

The Statement's pre-amp section is quite good; and I've heard from Wally that John Tucker does not like to modify the Statement into the Statement Plus model (the $5K pre-amp upgrade). Still, I'd never thought of running a separate pre- into my LSA.

Is the SimAudio P5 that much of an upgrade?

Dekay - simao , Thanks for taking the time to post on my inquiry . 
The LSA  is used . I traded for it . 
Before the trade i had bought the Simaudio p5 preamp and it arrived after the trade .I have a few amps i tried the p5 on and wanted to hear it with the LSA once i read the Positive Feedback article 
The Moon p5 / LSA combo sounds great with only 40% of my music . Just so so with the rest . 
I installed a pair of Siemens tubes in the LSA which sound much better to me than the EH that were installed .
LSA is a fine integrated .

@maplegrovemusic That it is. I'm on the lookout for a specific Triode Corporation integrated to perhaps replace it only because Robert Lee at Acoustic Zen raved about the synergy between my Adagios and Triode Corp. gear.