Adding a power amp to my CAP-100

[Telstar]

I'm in need of more power and bass control. Thanks to the flexibility of my CAP-100 I can use only its preamp section, both pre and power section alone or with a second power amp.

My Linn 5140 speakers are a pretty tough load, especially the woofer, nominally 90dB on 4ohm, but the woofer goes pretty low. I'm not sure which is the sweet spot for my speakers, but I think 150W (on 8ohm) to be probably too few, hence to rule out the ca-150. AFAIK Classé amps are not rated at 2ohm but the best ones should be almost linear.

I'm considering one of these (in brackets the nominal watts@8/4/2ohm)

- CAM-200* (200W/400W/?)
- CA-200 (200W/?/?)
- CA-150 (150W/300W/?)
- 25 (250W/500W/?)
- 15 (175W/350W/?)

[* probably the best sounding, but two monos have a very bad WAF]

I would like opinions about the sound, in particularly doing this upgrade I would like to improve bass control, enlarge the soundstage (the cap100 is a bit "small" and forward) and add more warmth, preserving or improving the transparency and detail that i love in my integrated.

Other suggestions are also welcome, but consider that my budget is limited and that the other elements of my system have been already optimized (cables, etc are not a weak link).

[Glen B]

IMO the CA-200, Model 25 or CAM-200s should work fine. These amps are not specifically rated for 2 ohm operation but can handle difficult loads under normal listening conditions with no problem. Since you mentioned WAF, the CA-200 may be your best bet versus the Model 25, the former being reported as faster, more dynamic.

My PSB Stratus Gold i speakers have sensitivity in the mid-80s, drop below 4 ohms in the bass region and present a fairly difficult phase angle, yet my CA-300 drives and controls them with ease. Check out the Stereophile reviews of the CA-200 and CAM-350 which is similar to the CAM-200, for the test measurement results and reviewer opinion on sonics.

http://stereophile.com/solidpoweramps/297classe/

http://stereophile.com/solidpoweramps/304/

[Telstar]

I did read those reviews already Stereophile is usually my starting point.
I couldnt find a review of the 15 (not posted yet) and of the 25.

Also I had doubts whether the older models were generally better or worse. I think i'll go for the newer ones. I think the cam-200 monos would be my best bet, but that i more safely should opt for ca-200 or 201 (i prefer all black), and I have been told that these two are identical.

Edit: And I have also been told that there are differences not just aesthetics between ca-200 and 201. Do you know more?
Thanks

[Glen B]

The CA-200 and CA-201 are the same circuit. Classé has a history of making parts changes in a model run (like op amp and resistor substitutions for example) so you could say that any two pieces of the same model may have "differences" depending on date of manufacture.

[Telstar]

I'm waiting for Tom reply on this, but he will probably tell me that the differences are quite big

[Glen B]

I obtained a copy of the service manual for the CA-201 that includes all changes in the version with side heatsinks and compared the schematics to what I have for the CA-200.

I noted improved differential/gain stages in the CA-201 almost completely identical to that of the CA-301 as well as revised control board, addition of a DC blocking filter and changes to main board layout. DC offset adjustment pots have been eliminated. The input buffer, driver and output stages appear identical to that of the CA-200 except for a couple extra pairs of bypass caps in the output stage. There have also been a number of circuit updates listed through production life, mostly involving resistor, diode and cap additions and substitutions.

Older amps had a single main board. Later production has the main board divided between the two side heatsinks. A switch was also made from the older bolt-type output binding posts to WBT posts in latter production of the CA-201.

[Telstar]

"The CA-201 is almost identical to CA200 but for improved gain through control board update and protection circuit. It had a silver face plate with black rounded posts and black top cover at launch, and this changed to silver face plate with black square posts and silver top cover on later versions. WBT posts were also added later, replacing nut and bolt speaker posts. Due to different screw sizes and positioning an old version CA-201 can not be cosmetically upgraded and the addition of WBT posts not possible either."

I guess i should go for the latest revision of the CA-201. Trying to find one and listen

[Glen B]

"The CA-201 is almost identical to CA200 but for improved gain through control board update and protection circuit. It had a silver face plate with black rounded posts and black top cover at launch, and this changed to silver face plate with black square posts and silver top cover on later versions. WBT posts were also added later, replacing nut and bolt speaker posts. Due to different screw sizes and positioning an old version CA-201 can not be cosmetically upgraded and the addition of WBT posts not possible either."

Yes, it appears that is Tom's standard response.

"I guess i should go for the latest revision of the CA-201. Trying to find one and listen

What I would do.

[Telstar]

I have two other questions for people who knows the cap-100/150/151.

Besides bass control i find two other defects in my integrated, which are:
-small soundstage and not ideal separation between speakers (i.e. the speakers do not disappear from my room, and i use the balance a notch on the left to have focused, altough not centered voices)
-a tiny bit of grain

I have listened to different power amps, connected using the pre section of the cap-100 and all of them improved dramatically on these parameters.

I wonder how the ca-200 is respect to this.
It wont be easy to find an unit to audition in my area.