How to know if GAN-fet amp and Lyngdorf 2170 (as a Pre and Dac) are compatible

A two volt output on a DAC means.....two volts at 0db on a CD. This is the industry standard. If your amp has 26db of gain.....like the LSA Voyager does....then that means it has 20 times gain. There are practically no CDs that put out 0db on the CD. Usually peaks are around -6db.....so that means a 2 volt source is really only putting out 1 volt peaks on the highest recorded CDs. One volt times 20 times gain = 20volts......divided by an 8 ohm speaker that is 2.5 amps....times 20 volts = 50 watt peaks. If your speaker is 87db sensitive (this would mean maybe 83 at listening position then one watt gives 83......10 watts gives 93 and 100 watts gives 103db. 50 watts would be under 100db. This would be for the highest recorded discs. If the disc were recorded very low then you would not get anywhere near as much level of sound.......so it depends on the sensitivity of the speaker, how loud you listen and the recorded level of the recording. This is why I like to see at least 3 volts (1.5 in reality) on the output of a DAC or DAC pre to run straight into an amp. Another advantage for high sensitivity speakers. If you use a separate preamp then you usually have plenty of gain as most preamps have at least 6 db of gain......but the Lyngdorf?....you need to get a spec from the manufacturer. If I was a manufacturer of such a product I would have 4 volts as my standard. This way it can drive most speakers with most digital sources.

There are ways to increase the gain of an amp. The input buffer on some Class D amps is simply a buffer set for whatever gain the manufacturer wants. If you change a couple of resistors in the first buffer you can increase the gain 6 db or more......a no brainer on some amps. Some amps come with variable gain setting.....like the Premium-Audio amp has a choice of 26, 28 and 32 db gain.

Thanks Ric.  Very much.

I clarified my text to the factory rep based on the details in your post and when he replies I should have what I need to determine compatibility between the two pieces.

I have no experience matching separates but have been advised to confirm compatibility between amp and pre to avoid performance issues.

While this is certainly important, the other crucial factor is if the individual components provide the sound characteristics you’re looking for.  Just because components work together doesn’t mean they’ll necessarily sound good to you.  Just to state the obvious. 

Here is the reply from Lyngdorf:

“….1. The maximum output level of the analog output is 4V but you can reduce the level in the output setup to match the connected power amplifier.
2. The amplifier gain is dependent on the level setting in the output, so you have the option to match the max output level - or the gain if you prefer to call it that - to the power amp in use.

The volume control in the TDAI amplifiers is working in extremely small steps which means that even if you use only a fourth of the volume wheel scale there is very good resolution. Still it makes sense to match the output level to the power amp in use.”

Ricevs:

I can connect and go or I can play around adjusting the pre output.  But it seems to have your stated preference of 4v.

Soix:

I have experience bringing in new gear to evaluate for SQ performance in my system, whether it be streamer, integrated, power conditioner or tweaks, wires, etc.  The GAN-fet amp will be the first “separate” (amp or pre) I’ve ever connected.

So I thought it imperative to make sure no incompatibility between the two pieces would keep me from hearing the full potential of the amp in its current stock form as I assess whether it actually does sound good—hopefully very good, to me.  Over time, well past the honeymoon period.

But then great mods can breath new life into a piece, if one is fortunate to have access to such services.

They should be compatible between the pre amp and dac, the only reason would be if the gain of your pre amp would be optimized for analog souces only, in which case it would have too much gain for most digital gear, but if both are designed with both digital ins/outs you should be more than fine. The only situation you might run into a problems is if you ran fully balanced digital in which case you could end up with too much gain into some systems with efficient speakers.

How the amp is built has nothing to do if it will work ,
It has more to do with its Sonic signatures and which you are looking for.

It was never about the topology, if that is what you mean by “how the amp is built”.   Including the descriptive “GAN-fet”, which is Class D, in my OP was extraneous, for sure, so I can see why anyone might construe it as you did.

Everything worked out.  I ordered the amp.

It should be fine on paper. How the two actually sound together though can’t be known until they are setup and running in your room with your speakers.
My prediction is you should get very good results.

whwre you can run into preventable technical issues that can result in higher distortion and compromised performance is with a high output impedance tube preamp. Input impedance of Class D amps can be as low as 10k ohm. You want that higher.

Thanks for posting, mapman.  I’ve never seen a member with more posts.  Let’s coordinate so I can do an OP that flips your postometer to 20k.

No rush. I’ve been at it for awhile, have lived and breathed this stuff since a kid, like to help people and learn myself, and always find topics of interest. If I win a $20000 Audiogon gift card for hitting 20000 posts that is a different story! 😉.