Amp/Preamp Asylum

Classe CA-101 runs hot (Abe) ?

207.69.115.40

[ Follow Ups ] [ Post Followup ] [ Thread: Display Email Next ] [ Amp/Preamp Asylum ] [ FAQ ]

Scott Redman

(A)

Abe,
Further down there was thread about your CA-100 running hot. I just got my CA-101 today. Have had it rocking the living room at appreciable levels for over 5 hours now, and it's barely warm to the touch.
It is really a different beast from my Assemblage ST-40 tube amp. Has more of a "in your face" sound to it. It's not bad, just very transparent compared to the ST-40. Maybe the ST-40 rolls off the highs a bit and I am used to it's sound. The CA-101 seems to present everything as it is, without much of a sonic character of it's own. It does not have the slight harshness that my Carver A-500x could exhibit at times.
System currently:
Classe CP-50 Preamp
Classe CA-101 amplifier
Philips SACD-1000 player
Yamaha NS-1000M monitors
DIY interconnects
Scott

Follow Ups:

My Krell KSA-150 was just warm to the touch but was a Class A amp. - RatFarm 17:08:57 02/14/03 (8)
Running tempature isn't a good indicator of whether an amp is Class A or AB. If it runs warm but not hot, it could be due to inefficient heat transfer from the output stage to the heat sinks. Best to call Classe' on the subject.
On another note, Class A is no guarantee of good sound. I didn't end up liking the Krell too much. Very 'dry' sounding' compared to some Class AB designs I tried.
- The KSA-150 was only Class A up to approx. 25 wpc into 8 ohms. - TAFKA Steve 05:00:43 02/15/03 (4)
  I owned one and it dissipated only 400 W heat at idle. Despite Krell's claim of Class A operation to full output, the last Krells to actually do it were the heroically-massive KRS monoblocks.
  - Re: The KSA-150 was only Class A up to approx. 25 wpc into 8 ohms. - sogood 23:05:46 02/15/03 (1)
    TAFKA Steve, Do you know how far the Ksa-250 is class A also?
    - Almost 50 wpc Class A, the KSA-250 drew 7 amperes at idle.(nt) - TAFKA Steve 01:00:04 02/16/03 (0)
      .
  - That's it? My KSA-80 runs 40 watts into class-A - lwang 10:11:41 02/15/03 (1)
    based on emitter resistor voltage drop measurement and AC line power draw. But it runs pretty hot (meat thermometer dropped into a cylindrical gap of same size in heat sink gave reading of 130-140 deg,) even though it seem to have much more heat sink surface are compared to the KSA-150.
    - Yup, when converting from a KSA-150... - TAFKA Steve 15:19:47 02/15/03 (0)
      ...to an MDA-300 monoblock, Krell cranked the bias up a bit more to run closer to 60 W Class A (out of 300 W into 8 ohms).
      I think each KRS-200 monoblock dissipated 1.6 kW continuous at idle. Now that is a LOT of heat! Alastair Robertson-Aikman of SME owns a pair to power 2 Quad ESL63's/channel.
      To do class A with a smaller chassis, you need a fan for cooling (yuck).
- Re: My Krell KSA-150 was just warm to the touch but was a Class A amp. - AbeCollins 18:52:11 02/14/03 (2)
  I agree. There are outstanding class AB biased amps out there and they are usually more "practical" from a power consumption and heat dissipation stand point compared to full class-a. My AB biased push-pull tube amp sounds better to me than the class-A biased Aleph 3 and the tube amp draws less power.
  - Re: My Krell KSA-150 was just warm to the touch but was a Class A amp. - NEAR SOTA 12:23:12 02/15/03 (1)
    Are you using your Tubes to drive Klipsch speaker's? I would imagine that the Pass Amp would do better with other speaker's instead of Horns.Just wondering if that be the case.
    No amp in whatever class is a guarantee of good sound.There are synergy issues not to be over looked,but Krell's,Pass and a few other's usually get Class A ratings because of the non-synergy issues they overcome with most speaker's.Just a thought.
    I am looking at Monarchy's for my next set of amps and they are Class A.Never owned a Class A amp before,but my amp is Bias'd toward Class A and is very transparent for a modified mid-price piece of gear and it's A\AB.
    NS
    - Re: My Krell KSA-150 was just warm to the touch but was a Class A amp. - AbeCollins 08:06:56 02/17/03 (0)
      No, I'm driving regular ole dynamci speakers that have a couple 8" drivers and a concentric brass tweater. They are Tannoy Definition D500 speakers. The class-A biased 30-wpc Aleph 3 is an outstanding amp but in my application I prefer the AB biased push-pull 70-wpc CJ Premier 11a tube amp.
Re: Classe CA-101 runs hot (Abe) ? - AbeCollins 15:15:42 02/14/03 (0)
Scott - When I had my Thiel CS 1.5 speakers and the Classe CA-100, the amp ran a little on the warm side but never too hot. At least not compared to my Pass Labs Aleph 3 which is biased 100% class-a 100% of the time.
I did notice an over all improvement going to the larger CA-200 amp but again, this was with my less than efficient Thiel speakers. The Thiel CS 1.5's are rated at 4 Ohms nominal with a sensitivity of 86dB. If your speakers are somewhat efficient, the CA-101 should be more than adequate.
I think I was commenting on how hot the Aleph 3 runs. The Classe amps are more or less biased class AB and shouldn't run too hot.
Congrats on the new setup!
http://www.AudioAsylum.com/forums/amp/messages/11529.html

This post is made possible by the generous support of people like you and our sponsors:

DIY Hifi Supply

[ DIY HiFi Forum ]

You can not post to an archived thread.