Cat Ultimate MkII Preamp mods for volume control?


This question is directed to those who may own the CAT Ultimate preamp. I am very satisfied with this pre (line stage only).The one thing that I feel is a negative is that the volume control has few steps, which for the most part does not bother me. It is when I have company, or am eating dinner and would like background music at low settings where the problem then arises. The difference between the lowest setting and no volume is enough to not listen to music at these times. I don't know if anyone has experienced this, or if there is a modification for a different contol unit. I don't know if Ken Stevens had a reason behind the few stepped control unit, but in my opinion a few more wouldn't hurt. Any suggestions?
proclaim123
Proclaim123 The Placette RVC is used in series between the DAC and the CAT. I disagree with Rfogel8 statement regarding the use of another volume control and the sound quality suffering - at least in relationship to the Placette RVC. I absoultuely cannot tell the difference between the sound quality of the CAT straight up and with the use of the RVC to attentuate the volume (two other friends have tried the experiment with me, they cannot tell the difference either). Now perhaps there is some difference and we just can't hear it, but what you do get is remote control (with no active circuitry to interfere with the sound) and 128 discrete steps of volume control and that range can be adjusted by simply using your CAT attenuator to affect the high and low volume range - in other words, an incredibly fine control of volume gradations, and remote to boot. As well all know, we must all judge with our own ears - all I can say is Placette will let you try it for 30-days and you make up your own mind. P.S. You can also play the Placette straight (no CAT) and if you don't need source switching, have high impedance amplifiers, and don't need to run long interconnects you just might prefer the RVC to the CAT. Don't take my word for it, try it.
Thanks for the tried and true responses!! It seems this will be the road I'll take with the CAT and most likely have Ken do the work since I know it will be done right.
Proclaim123
I had my Cat MK II updated to a series III and when this was done I had Ken install the resistors in the volume control. I was one of the first to have this done and what a difference this made. Now the useable range of the volume control was all the way up to 3 o'clock for loud listening which before was at 9 o'clock. Late night listening sessions at low volume was now between 8 and 11 o'clock. Prior to Ken's resistor installation the volume increase between notches was simply too big of a jump.
I say go for the mod, you will be happy.
Good luck.
I've had every Cat(with phono) going back at least six generations and currently own the Ultimate II. I definitely would NOT use any other volume control other than one provided by Ken otherwise sound quality WILL suffer.

Having the CD Taper is definitely a step in the right direction giving you smaller adjustments in gain. I would take Ken's advice and send your unit back to him to have the lower gain(6db less)stepped attenuator installed. Having to spend the extra $375 is a bitch but at least you'll know it was done correctly and your problem will be solved.

The reason you're having the problem with too much gain at the low end of the volume control is that most digital sources today provide way more output voltage than what's necessary. If you were running a passive unit I could see it but passives have pretty much disappeared. Reason is, they're really not very dynamic without a buffer stage and usually quite boring after you've lived with them for a while. I know from experience having owned a couple really good ones before switching to the Cat.

The Cat's 26 db of gain compared to around 20 db with most other brands is part of the problem but if you were using his phono stage with 46 db of gain to drive a MM or med. output MC cartridge, there'd be no problem. You'd be glad to have the extra gain in the line stage. Many people buy the full function Cat because for a few hundred dollars more you get a very good phono stage and eliminate the need for another box and interconnects.

My advice is to bite the bullet and have Ken do the work. Next time you order a new Cat specify CD Taper and minus 6 db stepped attenuator. Ken is very aware of the "problems" some people have with gain and should really point out the options that are available.

Good luck and happy listening.
Just an update for those interested. I spoke with Ken Stevens from Convergent Audio today. His suggestion would be to have resistors installed on the volume control unit itself which would lower the gain by 6db overall. This install could either be done by C.A.T. themselves or he would send out the resistors for free to either have myself or another qualified person install. Ken charges a minimum of $375 for an "over all check up" of the unit and would include the resistors with that. The check up would include a diagnostic check with minor repairs if needed.
He also stated that the Placette remote volume control unit could be used on the tape loop only, but wasn't too keen on the idea.
Unfortunately, what you are dealing with is endemic to a a high gain pre-amp with a stepped attenuator. The stepped attenuator is reported to sound better, but coupled with the high gain inherent in the design, it makes for very large volume changes at the low end. Its actually one (not the only one) of the reasons why I sold mine. You can put a fixed attenuator in line btwn the pre and the amp and it will help some. I used a 12 dB unit and it made it acceptable, but it was clumsy with heavy interconnects and puts a lot of stress on the rcas. YMMV.
Tubes108
I contacted Conv. Audio today and spoke with one of their technicians. The preamp that I have is line stage only which I was informed has the CD taper volume control unit. This CD taper volume control unit has smaller changes built in the unit (meaning more) vs. the Ultimate pre w/phono which has fewer stepped changes. I was advised to e-mail Ken to see if there is any other way through Conv. Audio themselves to achieve this. I'll keep you posted.
Hi Proclaim123. No, I have not heard the other vol control. I am aware of it as it was mentioned as an option when I got my Ultimate. I went with the stock control. I am sure that if you call CAT, they could provide any tradeoffs, should there be any, with the use of the other vol control.

Please let us know what happens. Best of luck!
Thanks for your input, there are a few questions though:

Tubes108
Since I have not had a chance to call Ken Stevens have you had a chance to hear an Ultimate with a "higher end" volume control unit offered by Convergent Audio?

Pubul57
I have also read your thread on active/passive pre's (I'll be honest - I don't know what the difference is). Are you currently using the Placette RVC with the CAT, also being that the CAT is an active pre as stated would the mix of a passive volume control change the sonic character of the Ultimate?
The web site for the Placette RVC states that this is a low cost unit for $1,000.00. I may be missing something here. Maybe for hi end audio this is low cost control. I wonder if Convergent Audio does have a "higher end" control unit what the price would be.

Thanks for you help
I tried the Placette RVC and it will work wonderfully well as a volume control, as well as providing you with remote control. I have the CAT Ultimate and this set up sounded great, but the Placett on its own might be even better in the right system.
You can also add a placette
check this out:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1159194844&read&3&4&
Hi. I believe that you can get a diff volume control directly from CAT. The other one, which is optional when purchasing a preamp, has more steps at the lower end of the control than the stock volume control has.