[low.pfile]

I am a dummy when it comes to impedances, voltages, etc. I hear matching is good. I am trying to learn more. What defines matched components (high with high?  high with low? equal?) </dummy>

I have read that the RWA Signature 30.2 Integrated with attenuator has a 20k input impedance vs. the Signature 30.2 Amp's 100k.  Now I am trying to determine which version is more optimal with either a Modwright 9.0se or Isabella pre-amp. What do I gain with the Power Amp version?   Obviously, I have the benefit of not immediately needing a pre-amp if I get the Integrated version.

Context: Digital Server w/ Monarchy NM24 DAC or Wavelength Brick DAC front end ...... Devore Super8 (90db/w/m-8ohm)

I am needing to make some decisions soon as opportunities may be lost if I don't. In the process of a putting together my 2nd system.

Thanks,
ed

[saisunil]

Without even looking into impedence matching ...

You probably want to pick a power amp instead of an integrated amp if you are going to go for a separate Pre.

My 2cents

[CSI]

I am a dummy when it comes to impedances, voltages, etc. I hear matching is good. I am trying to learn more. What defines matched components (high with high?  high with low? equal?) </dummy>

I have read that the RWA Signature 30.2 Integrated with attenuator has a 20k input impedance vs. the Signature 30.2 Amp's 100k.  Now I am trying to determine which version is more optimal with either a Modwright 9.0se or Isabella pre-amp. What do I gain with the Power Amp version?   Obviously, I have the benefit of not immediately needing a pre-amp if I get the Integrated version.

Context: Digital Server w/ Monarchy NM24 DAC or Wavelength Brick DAC front end ...... Devore Super8 (90db/w/m-8ohm)

I am needing to make some decisions soon as opportunities may be lost if I don't. In the process of a putting together my 2nd system.

Thanks,
ed

As usual, the definitive advice should come from the mfg. himself. I'll offer the general rule of thumb for pre to amp matching. Low to high. If the power amp has an input impedance well above 10,000 ohms or so it should work well with just about any preamp on the market - including older all-tube units with largish output impedances (a high output impedance for an audio preamp would be 1500 ohms or more). The results of a mismatch (amp too low, preamp too high) could be rolled off highs and a slight loss of power. The numbers become more important with long interconnect runs between the two (say over 3 meters). Passive "preamps" are a special case since the amp only "sees" the impedance of the source components and cables so system building becomes a bit trickier.

I doubt if there is much difference, if any, between the RW power amps and the somewhat lower impedance integrated 30.2 but I'll leave that for Vinnie to comment on.

[low.pfile]

Thanks CSI.... that didn't go over my head.

[low.pfile]

Yeah, hoping Vinnie has a moment to chime in on this (in between designing and building).

[Flashman]

I am a dummy when it comes to impedances, voltages, etc. I hear matching is good. I am trying to learn more. What defines matched components (high with high?  high with low? equal?) </dummy>

I have read that the RWA Signature 30.2 Integrated with attenuator has a 20k input impedance vs. the Signature 30.2 Amp's 100k.  Now I am trying to determine which version is more optimal with either a Modwright 9.0se or Isabella pre-amp. What do I gain with the Power Amp version?   Obviously, I have the benefit of not immediately needing a pre-amp if I get the Integrated version.

Context: Digital Server w/ Monarchy NM24 DAC or Wavelength Brick DAC front end ...... Devore Super8 (90db/w/m-8ohm)

I am needing to make some decisions soon as opportunities may be lost if I don't. In the process of a putting together my 2nd system.

Thanks,
ed

I have the Monarchy NM24 tube preamp/tube DAC and had the same question as you on impedance matching with my Sig 30.2 integrated amp (not power amp).  Here's what C.C. Poon, the designer/owner of Monarchy Audio told me in an e-mail:

"Technically you want a low output impedance running into a high input impedance.  The output impedance of the NM24, at 300 Ohm, would work great with the input impedance (Sig 30.2 integrated) at 20K Ohm."

I don't know whether this suggests the higher impedance of the Sig 30.2 in power amp mode is even better for impedance matching.  Vinnie or someone else would have to answer that, but the good news is that the NM24, which I assume you have, works fine with the Sig 30.2 in its integrated mode.  Since I just received the NM24 yesterday, my only issue is trying to find the right balance between the Sig 30.2 volume setting and the optimal volume control on my NM24.  Hope this helps.

[Vinnie R.]

Hi low.pfile,

I am trying to learn more. What defines matched components (high with high?  high with low? equal?) </dummy>

The general rule of thumb is that you want the input impendace of your amplifier to be at least 10x greater than that the stage before it (preamp, or source).  As CSI points out, "low to high," meaning a low output impendace of a source or preamp feeding into a high input impendace the next stage (amplifier).

The Signature 30. with built-in remote volume control has an input impedance of 20k.  Just about any active preamp should not have a problem driving this.  The benefit of the built-in volume control is this: many active preamps on the market today seem to have A LOT of gain (too much, IMHO  )!  This means that you'll find that the music gets quite loud earlier on the preamp's volume control, so you do not have much usable range out of the volume control.  Having a Signature 30.2 with built in volume allows you to set this volume control to a position that gives you the most usable range out of your active preamps's volume control. 

If you are using a passive preamp or an active preamp that is not "jacked" with gain  , the 30.2 power amp (no volume control) would be a fine choice.  I do offer the Signature 30.2 power amp and 70.2 monoblocks with 24dB of gain, or 30dB.

I hope this helps,

Vinnie

[low.pfile]

I have the Monarchy NM24 tube preamp/tube DAC and had the same question as you on impedance matching with my Sig 30.2 integrated amp (not power amp).  Here's what C.C. Poon, the designer/owner of Monarchy Audio told me in an e-mail:

"Technically you want a low output impedance running into a high input impedance.  The output impedance of the NM24, at 300 Ohm, would work great with the input impedance (Sig 30.2 integrated) at 20K Ohm."

Thanks for that info Flashman, Though I am not using the linestage section of my NM24, only the Tube DAC section. I am curious how you like using yours that way. drop me a PM or review it here on AC.

enjoy your music, ed

[low.pfile]

The general rule of thumb is that you want the input impendace of your amplifier to be at least 10x greater than that the stage before it (preamp, or source).  As CSI points out, "low to high," meaning a low output impendace of a source or preamp feeding into a high input impendace the next stage (amplifier).

The Signature 30. with built-in remote volume control has an input impedance of 20k.  Just about any active preamp should not have a problem driving this.  The benefit of the built-in volume control is this: many active preamps on the market today seem to have A LOT of gain (too much, IMHO  )!  This means that you'll find that the music gets quite loud earlier on the preamp's volume control, so you do not have much usable range out of the volume control.  Having a Signature 30.2 with built in volume allows you to set this volume control to a position that gives you the most usable range out of your active preamps's volume control. 

If you are using a passive preamp or an active preamp that is not "jacked" with gain  , the 30.2 power amp (no volume control) would be a fine choice.  I do offer the Signature 30.2 power amp and 70.2 monoblocks with 24dB of gain, or 30dB.

I hope this helps,

Vinnie

Applying the rule of thumb.....

Modwright  SWL 9.0SE Linestage Preamplifier: Output Impedance: ~600ohm

Therefore, for the MW pre the desired impedance would be greater than 10 x 600 = 6000(6k)

So the input impedance of the 30.2 AMP is 100k and the 30.2 Integrated is 20k. so both are acceptable based on a rule of thumb. Cool.

I am going with a MW 9.0SE for pre, as it is available now. I may check out an isabella w/DAC in the future.

Also I am going with the RWA 30.2 AMP version.


Thanks again
Ed