?22 as a preamp?

[Salt Peanuts]

I'm planning on using my ?22 as a preamp with McIntosh MC2100 and Eminent Tech LFT-8b. Just wondering if anyone around here knows how ?22 stacks up as a preamp. I'm hoping to get a standalone unit, but that won't be for a while with recent and upcoming non-audio expenditures.

Oh, and anyone has thoughts on Promitheus Audio TVC? It has rather attractive price and seems to be well-received (though it would be nice if it had a remote).

[Grand Enigma]

hmmm someone appears to be strolling down the same path I have. The Promitheus TVC is a great preamp as long as you get enough gain from your source and amp.

Are you looking for a preamp that doubles as a headphone amp or will just a preamp do? I have gone back and forth with that many times in my rig.

[Salt Peanuts]

At this point, I'm looking for just a preamp, as I plan on keeping ?22 as my headphone amp - it works rather well with RS-1 and K1000.

If ?22 works well as a preamp, I may see about getting a remote-controlled volume control installed. Of course, with my lack of experience with preamps (and speaker setup in general), I don't really have a god point of reference for preamp performance.

[swt61]

If memory serves I think fierce_freak used one as a preamp and quite liked it.

[humanflyz]

I'm planning on using my ?22 as a preamp with McIntosh MC2100 and Eminent Tech LFT-8b. Just wondering if anyone around here knows how ?22 stacks up as a preamp. I'm hoping to get a standalone unit, but that won't be for a while with recent and upcoming non-audio expenditures.

Oh, and anyone has thoughts on Promitheus Audio TVC? It has rather attractive price and seems to be well-received (though it would be nice if it had a remote).

I had a S&B TX-101 MKIII TVC: it was great...in its volume range, but I wanted more volume, and it couldn't keep up.

[Grand Enigma]

I had a S&B TX-101 MKIII TVC: it was great...in its volume range, but I wanted more volume, and it couldn't keep up.

Just get a step up or a TVC with a bit of gain

[aerius]

Or bump up the gain of the amp itself.

[swt61]

Or bump up the gain of the amp itself.

aerius I love ya buddy, but I looked and looked and I couldn't find any sarcasm in this post. Please don't make a habit of this.

[deepak]

Haj, Kevin Gilmore sent me some very good advice regarding the B22 as a preamp. I can pass along that info if you'd like, but I'm not sure if he wants that information made public or not.

The skinny was that it wouldn't make a great preamp because of the high noise level. Nanoha noted some noise using the beta22 as a pre to an F1 as well. This info is somewhere in a thread I made looking for a preamp for a speaker setup.

[n_maher]

Haj, Kevin Gilmore sent me some very good advice regarding the B22 as a preamp. I can pass along that info if you'd like, but I'm not sure if he wants that information made public or not.

I thought kevin had already posted that somewhere here? Looked and can't find it but I'd swear we had part of this discussion before... Yup, found the other reference to Kevin's comments in your "low power SET" thread. I know that the measured noise on the output of the beta22 is pretty fricken low and that the measured example was setup to be a head/speaker amp, not a preamp. Still, please feel free to PM me what Kevin had to say, I'm curious.

The skinny was that it wouldn't make a great preamp because of the high noise level. Nanoha noted some noise using the beta22 as a pre to an F1 as well. This info is somewhere in a thread I made looking for a preamp for a speaker setup.

It makes one wonder if the b22 in question was setup to be a preamp? I have no idea what Nanoha's beta was setup like but I'm guessing it had the stock gain of 8 which is ridiculous for a preamp. Beyond that it's really a speaker amp first, absurd headphone amp second. Would you try and use any other speaker amp as a preamp? And I have to wonder about anyone claiming to get noise out of one and whether or not they built a single-chassis amp which is damn near impossible to make silent without a shielded trafo. That's user error, not amp error.

So I guess what I'm saying is that expecting something that was built to drive moderate speaker loads to be a great preamp seems odd to me. But, properly configured the beta22 should make an excellent preamp. Haj, yours would likely take a little tweaking but at least it's starting life as a two box design which should help.

[luvdunhill]

while we're on this discussion, take a moment to compare the M3 and ?22 from the data at these links:

http://www.amb.org/audio/mmm/rmaa_mmm_8.html

http://www.amb.org/audio/beta22/rmaa_beta22_8.htm

both are tests results into a 8? load.

I won't connect the dots for you, but it's pretty interesting data.

[deepak]

I thought kevin had already posted that somewhere here? Looked and can't find it but I'd swear we had part of this discussion before... Yup, found the other reference to Kevin's comments in your "low power SET" thread. I know that the measured noise on the output of the beta22 is pretty fricken low and that the measured example was setup to be a head/speaker amp, not a preamp. Still, please feel free to PM me what Kevin had to say, I'm curious.

It makes one wonder if the b22 in question was setup to be a preamp? I have no idea what Nanoha's beta was setup like but I'm guessing it had the stock gain of 8 which is ridiculous for a preamp. Beyond that it's really a speaker amp first, absurd headphone amp second. Would you try and use any other speaker amp as a preamp? And I have to wonder about anyone claiming to get noise out of one and whether or not they built a single-chassis amp which is damn near impossible to make silent without a shielded trafo. That's user error, not amp error.

So I guess what I'm saying is that expecting something that was built to drive moderate speaker loads to be a great preamp seems odd to me. But, properly configured the beta22 should make an excellent preamp. Haj, yours would likely take a little tweaking but at least it's starting life as a two box design which should help.

I believe Nanoha's friends B22 preamp was designed specifically as a preamp to drive his F1. I have that in PM as well somewhere. YGPM.

[grawk]

while we're on this discussion, take a moment to compare the M3 and ?22 from the data at these links:

http://www.amb.org/audio/mmm/rmaa_mmm_8.html

http://www.amb.org/audio/beta22/rmaa_beta22_8.htm

both are tests results into a 8? load.

I won't connect the dots for you, but it's pretty interesting data.

The 330 ohm loads are more useful when considering both as a preamp.

[n_maher]

while we're on this discussion, take a moment to compare the M3 and ?22 from the data at these links:

http://www.amb.org/audio/mmm/rmaa_mmm_8.html

http://www.amb.org/audio/beta22/rmaa_beta22_8.htm

both are tests results into a 8? load.

I won't connect the dots for you, but it's pretty interesting data.

Just an FYI, you can't remote link to any of AMB's amp pages, they'll all take you to the root directory. Also, Ti freely recognized early on that the M

[Pars]

IHaj, Kevin Gilmore sent me some very good advice regarding the B22 as a preamp. I can pass along that info if you'd like, but I'm not sure if he wants that information made public or not.

I'd be interested in reading that also, if you don't mind.

Chris

[luvdunhill]

Ti freely recognized early on that the M

[n_maher]

yup, this was my point.

And this goes back to my original question, is it really any surprise that what is basically a speaker amp doesn't make the best preamp? Although I'm still shocked to hear anyone claiming to hear audible noise out of a properly built beta22.

[luvdunhill]

And this goes back to my original question, is it really any surprise that what is basically a speaker amp doesn't make the best preamp? Although I'm still shocked to hear anyone claiming to hear audible noise out of a properly built beta22.

well, more like an integrated amp, but yes I am in agreement. swt61 is planning on trying it out, and this is one of the reasons his beta22 is at my house right now.

[n_maher]

well, more like an integrated amp, but yes I am in agreement. swt61 is planning on trying it out, and this is one of the reasons his beta22 is at my house right now.

What are your planned mods? Lower the supply voltage (assuming it's at the stock 30V now) and drop the gain down to 2?

[Salt Peanuts]

Deepak, if you can along the info from Kevin in regards to B22 a preamp, I'd appreciate it.

I'm resigned to the fact that I may have to look elsewhere since my B22 is set at gain of 8, IIRC, mainly for driving K1000 and as such, I don't really want to lower that.

[luvdunhill]

What are your planned mods? Lower the supply voltage (assuming it's at the stock 30V now) and drop the gain down to 2?

yes, in response to the above two posts there is a quandary on what to do, if you're looking for a true preamp.

However, in Steve's case he's planning on using it as a integrated amp, not a true preamp.

What about using the beta22 as a preamp into something like a Pass F4? In this case, there isn't any voltage gain in the amp, so it might be a match made in heaven.

[kevin gilmore]

Noise comes from a lot of different sources. A resistor generates noise all by itself due to the

temperature. This is called johnson noise. The only way to reduce this noise is to lower the temperature

of the device, and many ultra low noise preamps put much of the active circuitry on a peltier element to

acomplish this. Output devices generate noise which among other things is dependent on the

amount of current flowing thru the devices. Then there is shot noise, also dependent on the amount

of current thru the device. All things being equal, an output stage biased at 200ma is going to have

a lot more noise than an output stage biased at 10ma.

Its not the B22 as such that is the problem. Same thing using a Dynahi as a preamp. Regardless of what

gain you use in your b22 the output stage noise will still be there.

One of the reasons i parallel many smaller devices is to get the noise level down.

[luvdunhill]

Noise comes from a lot of different sources.

don't forget about noise

[n_maher]

Thanks for the input Kevin.

[swt61]

However, in Steve's case he's planning on using it as a integrated amp, not a true preamp.

Nate my hope was to use my Beta22 to drive the new Omega Grande 6's I've got comming. And what I wanted was to also send a signal to my powered subs so that they would both be attenuated by the Joshua Tree.

However if this isn't the best solution I'm more than willing to consider alternatives.