High Current Amp/Pre-amp recommendation needed - Power for Infinity Kappa 9 pair

[edisonbaggins]

As long as you don't need anything other than volume control the attenuator will work fine.

But there is another way to do this with what you have now. It didn't occur to me until I saw what you are calling an attenuator.

Run your CD player output direct into the attenuator. Get some RCA Y splitters and connect them to the stereo outputs of the attenuator. You will use the attenuator to control the overall volume. Connect the splitters to the inputs of the two amps, Adcom on bottom, tubes on top. The Adcom will run at a constant gain with volume controlled by the attenuator. The tube unit has its own volume control which you will use to adjust its relative gain to the Adcom. In effect, you will set the tube volume to where it needs to be to provide sonic balance between woofers and tweeters. Then, once found, you need never change it. The Schit attenuator will control the volume of both amps.

There may be some issue with the attenuator being a passive device as the Y splitters will affect the impedance it sees at the amp connections, but ill bet the impedance changes with the volume knob position anyway. It will work. It may even give satisfactory results. and it requires you to buy nothing further to try it out.

EDIT: Oh yeah, after reading par4kens post i see he had the same idea. And yes, if you are going to use an active crossover just place the attenuator before it in the chain.

I have splitters. Just need to introduce the miniDSP in to the signal chain somewhere. It is 2x4, so essentially a splitter. Maybe all I need to do is change where I have my Shiit Sys right now.

 

[LuvMyQuad]

I have splitters. Just need to introduce the miniDSP in to the signal chain somewhere. It is 2x4, so essentially a splitter. Maybe all I need to do is change where I have my Shiit Sys right now.

Yep. there ya go.

 

[LuvMyQuad]

Another comment. With respect to bypassing the passive xover in the speakers, All you really need to do is connect speaker cables from the drivers themselves to the amps. I believe in your case there are two woofers. They may have staggered xover points. So what you can do is just disconnect the internal lead going from the xover to the tweeters. Tape it off so nothing shorts out. Connect a cable from the tweeter to the tube amp. Now the 2x4 provides the hi/lo crossover, and the passive xover in the speaker still provides the xover for the two woofers. This gives you most of the benefit of true biamping

If one of those woofers is a passive radiator, its essentially a 2 way speaker anyway.

If the speaker is ported, you can run the tweeter lead right out the port. No holes.

You need not modify anything that cant be returned to the original build. Even the connections to the tweeter may be mechanical clips. Just solder on a set of clips to the new speaker lead and you are in business.

 

[edisonbaggins]

Another comment. With respect to bypassing the passive xover in the speakers, All you really need to do is connect speaker cables from the drivers themselves to the amps. I believe in your case there are two woofers. They may have staggered xover points. So what you can do is just disconnect the internal lead going from the xover to the tweeters. Tape it off so nothing shorts out. Connect a cable from the tweeter to the tube amp. Now the 2x4 provides the hi/lo crossover, and the passive xover in the speaker still provides the xover for the two woofers. This gives you most of the benefit of true biamping

If one of those woofers is a passive radiator, its essentially a 2 way speaker anyway.

If the speaker is ported, you can run the tweeter lead right out the port. No holes.

You need not modify anything that cant be returned to the original build. Even the connections to the tweeter may be mechanical clips. Just solder on a set of clips to the new speaker lead and you are in business.

The C-8's are 1 tweet, 2 woofs.
The Veritas 2.3's are 1 tweet, 1 mid, 2 woofs.
In either case, removing the jumpers isolates the woofs from the higher speaks. Is that basically what you mean? In both units there's a passive between the woofs. In the veritas there's also one between the mid and tweet.

 

[LuvMyQuad]

The C-8's are 1 tweet, 2 woofs.
The Veritas 2.3's are 1 tweet, 1 mid, 2 woofs.
In either case, removing the jumpers isolates the woofs from the higher speaks. Is that basically what you mean? In both units there's a passive between the woofs. In the veritas there's also one between the mid and tweet.

Even better. Then you need do nothing to isolate the tweeters.

 

[edisonbaggins]

Even better. Then you need do nothing to isolate the tweeters.

Trying to wrap my mind around using the Shiit Sys to control volume of an amp and an integrated amp.
So, I think of the amp as being "wide open" on volume. It's just full blast all the time, thus the need for an external volume control.
What to do with the integrated? I set it somewhere between 0 and wide open, then leave it, I suppose. But how do I determine where? Try 0 and dial it up until it sounds right?
I do have a calibrated mic and REW. I should employ those, at some point.

 

[LuvMyQuad]

But how do I determine where? Try 0 and dial it up until it sounds right?
I do have a calibrated mic and REW. I should employ those, at some point.

yes and yes

 

[edisonbaggins]

Ok, new signal path:
Sony CD changer --> Schit Sys volume control --> miniDSP 2x4 HD --> 1) --> Adcom GFA 5300 (low frequency high current 80W SS amp) 2) Jolida JD302B (high freq integrated tube amp) 1) --> woofers of each tower, 2) --> tweaters of each tower

Got it sounding balanced at a fairly thumpin' volume. Seems like, when bringing the Schiit Sys up from zero, that the low amp kicks in right away, but the high amp takes some volume to show up (could it be, because the low amp is "wide open" and the high amp just above 50%, that the high amp will "take over" as the volume of the Schitt is increased? That said, at volume, this sounds great, to my ears and the whole thing sounds a bit more cohesive, somehow. Maybe running the entire signal through the Schiit adds that cohesion. Something with the ohms or whatnot?

Ps. I like typing and saying "Schiit".

 

[GOS]

Ok, new signal path:
Sony CD changer --> Schit Sys volume control --> miniDSP 2x4 HD --> 1) --> Adcom GFA 5300 (low frequency high current 80W SS amp) 2) Jolida JD302B (high freq integrated tube amp) 1) --> woofers of each tower, 2) --> tweaters of each tower

Got it sounding balanced at a fairly thumpin' volume. Seems like, when bringing the Schiit Sys up from zero, that the low amp kicks in right away, but the high amp takes some volume to show up (could it be, because the low amp is "wide open" and the high amp just above 50%, that the high amp will "take over" as the volume of the Schitt is increased? That said, at volume, this sounds great, to my ears and the whole thing sounds a bit more cohesive, somehow. Maybe running the entire signal through the Schiit adds that cohesion. Something with the ohms or whatnot?

Ps. I like typing and saying "Schiit".

Me too! Schitt's Creek. Great show. lol

 

[Soundfield]

There are multiple problems with mixing two different types of amplifier to drive a single speaker. Foremost amongst them being how do you know they are in phase? There is no standard for phase polarity - some amps invert, some do not.

 

[edisonbaggins]

There are multiple problems with mixing two different types of amplifier to drive a single speaker. Foremost amongst them being how do you know they are in phase? There is no standard for phase polarity - some amps invert, some do not.

Because I know my reference recording and nothing is missing? If you have a test that can be performed, pray tell!

 

[Soundfield]

If you have a test that can be performed, pray tell!

Simple, but requires an audio signal generator and a dual channel oscilloscope.

 

[edisonbaggins]

Simple, but requires an audio signal generator and a dual channel oscilloscope.

Simple, to you, perhaps...

 

[kfbkfb]

One way to find out if 2 given amplifiers are in phase with each other:

Hook up 1 amp to a speaker, the other amp to another speaker (of the exact same type/brand).

Feed the exact same signal to each amp at the same time (can be any signal, music, AM radio talk show etc.).

Listen between the speakers, if the sound is centered, both amps are in phase with each other, if the sound is diffuse, they are out of phase.

Using amps that are out of phase with each other for bi-amping requires switching the speaker connections of either the bass or mid/treble amp, for example:

Bass amp:
Amp + out -> Speaker + in (for each channel)

Mid/Treble amp:
Amp + out -> Speaker - in (for each channel)

Switching the speaker connections in this way cancels the out of phase amp problem, hope this helps.


Kirk Bayne

 

[edisonbaggins]

Listen between the speakers, if the sound is centered, both amps are in phase with each other, if the sound is diffuse, they are out of phase.

Stereo image is sounding sweet. My wife thought the center speaker (of another system, but she didn't know that) was on!

 

[kfbkfb]

For the amp phase test, the same signal is fed to both amps (a mono AM radio broadcast works well).

Using an RCA line level Y adapter, feed the same signal to both amps and listen (as explained in the earlier post), the listening test will quickly reveal if the 2 amps are in phase or out of phase with each other.


Kirk Bayne

 

[edisonbaggins]

For the amp phase test, the same signal is fed to both amps (a mono AM radio broadcast works well).

Using an RCA line level Y adapter, feed the same signal to both amps and listen (as explained in the earlier post), the listening test will quickly reveal if the 2 amps are in phase or out of phase with each other.


Kirk Bayne

I get it! If I have any phasing concerns, I'll try that out.

In other news: the Parasound HCA-1500 has the woofers SLAMMIN'!!!