Please help - Impotence problem



Okay, forget my impotence problem, I have a more important issue with an impedance problem. Or do I? The latest incarnation of my system sounds truly fantastic and live but only at very high volume. I�ve read somewhere in the past that this may be a sign there�s an impedance mismatch somewhere in the system.

Can someone tell me how to find such a mismatch? I have two Counterpoint NP220 stereo amps bi-amped to a pair of Waveform Mach 13�s with an external crossover. My preamp is a Counterpoint SA-11. I�m assuming the Counterpoints work together so what could the problem be? Currently I�m just running digital (Sony SCD-777es) so I�m not concerned (yet) with my analogue rig.

(the two Counterpoint amps were SA-220's fully upgraded by Elliot with 'low sensitivity' instead of 'high sensitivity' but this is supposed to be the way to go if your preamp can handle it and mike elliot specifically recommends 'low sensitivity' if using with the SA-11 preamp.)

Overall instruments seem unbalanced with too much treble in the forefront, even when adjusting the crossover.

Could it be that the system is simply too bright and that's why i'm feeling the need to turn the volume control up so i can enjoy the midrange? Perhaps the problem is more with cables or a need for power conditioning? oh, god, i'm getting that feeling again. little help?!

Maybe someone out there has a good link for me to read up on this if the answer is too complex.

Thanks in advance.
kublakhan
Hello Marakentz- I have read many of your posts detailing your disdain for Counterpoint amplifiers. Could you please detail your experience in listening to them and the extent to which your opinions are based on first hand listening and hands on examination of these amplifiers?
Kubla:

Assuming that your new cables were installed less than 10 minutes ago, give them a hundred hours plus of playing time before going completely nuts.

The few cables that I have purchased "new" were congested/bright (quite a combo) and lacked bass fullness right out of the box.

Once the bass kicked in this was pretty much the way the system balanced out in the long run.

A friend of ours uses a Couterpoint amp (same era as yours, but stock) with an older Mod 3A and little 1.5 Thiels and his systems sounds quite good @ low/moderate listening levels.

If you are still not satisfied following this then I will be happy pull one of the BMI Whales for you to try on the Sony. This cord has plenty of bass/mid-bass when used with source gear (it makes low level listening quite pleasent).
Kubla. Which set of outputs are you using from the Counterpoint 11?

In spite of what you may have been told, the buffered outputs sound much worse. Even in very long runs (up to 40 feet) with those amps.

Use the direct out, I will try to remember which set of input jacks are the best sounding ones. They are all routed differently and one was clearly better.

Have you replaced the outboard jumpers with high quality wire and better connectors? Or if you're handy, solder across them internally with a piece of OFC copper wire.

If you have not replaced the output tubes with NOS 5692 tubes, you should. The Russian tubes typically found in these have terrible high frequencies.

Also, this uses a 6080 regulator. If it gets weak it severely damages the sound, long before it fails. NOS Mil grade may be purchased for about $10.00. If yours has not been replaced, I would do so.

You did not mention isolation. That particular preamp really responds well to Mod Squad Soft Shoes and Vibrapods.

You are welcome to call me if you need help.
1.Counterpoint is about to be broke.
2.Unstable DC offsetts make the amp oscillating. As far as I remember Mike used to give instructions how to bias an output stage(yes, transistors) and under the box it has a trim pots.
3.By bi-amping(horizontal) the stability is even more lost due to the added crosstalk and different load curve complexity -- would not recommend.
4.Built quality and reliability issues. Read out www.altavista.com to find out more about reliability of these amplifiers. I guess they're complete mess in that case.
5.The high sencitivity input stage that was removed is probably inverting cascade with neg. feedback that helps to stabilize driving tubes and so the output stage as well. Bring it back while Counterpoint still exists and + use direct out of your preamp as Albert suggests.
Albert, Dekay...Marakanetz...

Dekay, first. I feel really stupid but you are right. all my cables are new and already i'm noticing a difference as they're breaking in. i might start becoming a believer in cables. the smearing is going away, instruments are balancing out and low level detail is coming into focus. still, the lush tube midrange bloom i crave so much isn't there but i'm hoping.

Albert...thanks so much for detailing possible issues. i removed the buffered outs myself and yes, you're right, the direct outs sounded much better. however, mike recently installed XLR outs i needed to connect my crossover so i'm using those now. maybe they have to breakin also?

regarding tubes, i was told a while back that with the sa-11 first level mod (the mu circuit) the only audio critical tubes were the 4 outputs tubes that dont need to be biased anymore with the mod. i better check that i did in fact replace all of those. I know i have at least two RCA 5692 brown base nos tubes there. but regardless, the old system sounded better with the sa-11 as it is currently than the system sounds now so i'm thinking the problem is the amps, speakers or the cable breakin.

i'll check the regulator. as far as isolation the sa-11 is in a rack mount.

what do you think of marakanetz comments especially regarding biamping with these amps?

thanks guys...the sound is getting better every day and is sounding much better at around 3am. a power conditioner is on its way to help me extend the system to connect with my dedicated lines so that should help too. for now i'm just playing REALLY loud coltrane over and over late at night and it's actually very nice.

we;ll see. i'll keep you posted.