A few days or so ago, someone had revived an old Cary SLP 05 thread, and common to that discussion seemed to be the subject of too much gain.
My first question is: does compensating for too much gain by simply adjusting the volume knob knob down degrade the sonic quality?
My second (2 part) question relates to this quote from one of the replies in that thread:
A quick note to Pass Labs and they suggested a pair of Rothwell 10db balanced attenuators into the amp’s inputs.
What exactly do balanced attenuators do to resolve this issue, and if placed between the preamp and the amp, would they degrade the signal path & therefore the sonic result out of the speakers?
I am a relatively new owner/operator of a SLP05 and it is in front of one of the earlier Cary V12s. I did find those balanced attenuators on ebay for (I think I remember them being) $89 a pair, which I find totally doable. I am lsitening in a (very) near field room right now, and it seem as if I do have a lot of gain. Generally the big knob is on 9 o'clock plus or minus a little bit depending upon the source material I am listening to. I am using the balanced ins and outs to & from my SLP05 and I have been given to understand that using RCAs would reduce the gain somewhat. I do have some RCAs (I am presently using Kimber Silver Streak balanced interconnects) but my collection of spare RCAs is Kimber PBJ and Monsters.
For $89 should I try putting a pair of those of Rothwell 10db balanced attenuators into the balanced amp’s inputs?
I assume that is a typo, but maybe not? $140 + shipping maybe?
Anyway, have you been able to just fine tune with the big knob to find your "sweet spot"? Personally, I am thinking I can get the volume where I like it (although it does get there fast) but I just wasn’t understanding for sure whether the same volume would have a better sonic quality at, for example, 6-oclock versus 3-ocklock. Out of curiosity, did Cary Support offer anything on that part of the subject?
And how did you make out with the SLP05 malfunction you had posted about?
EDIT: OOPS on that, I just reread your reply and I see you are using the left & right input level pots to compensate with.
Hey @immatthewj, I didn’t realize you’re the OP. I think you had commented on the other Cary thread that I started. Anyway, I just had an email exchange with Cary support about this gain issue. Apparently they have a service called Gain Reduction on the unit to lower the gain by 6db. It costs $140 plus parts and labor. I decided I’m not going to do that, but it’s an option for you to think about.
Wow, thanks for all the input, everybody! I need to sit back & digest it.
@harpo75I actually did get this unit with The Ultimate Upgrade installed.
As far as the two balance controls, I have kept them maxed out for normal listening and in the past, with my SLP 90, I did find them useful for troubleshooting. As far as having them taken out of the circuit, in '99 I bought my previous preamp, the SLP90, second hand from a dealer. He told me it had been "hot rodded by Dennis Had." What that meant was that, among other things, the balance control pots had been taken out of the circuit. That SLP90 was a huge sonic upgrade for me, but I thought that most of the "hot rodding" that had been done to it made it totally unresellable (except to some dummy like me) so I called Cary up & spoke to Kirk Owens about undoing some of the mods. As far as the defeated balance controls went, Kirk told me that in theory (or on paper) there was some signal path degradation, but whether it could be heard was another matter. Sooooo, I did wind up having him put balance controls back in, and on the receipt for the work that he did, he referred to them as "improved quality L & R balance pots." (And I did always run them maxed out, but I did, quite often, find them useful for troubleshooting.)
I'm also a new owner of the Cary SLP-05, and I set the left & right gain of the unit to a relatively low level (around 3 o'clock position).
My power amp is the Parasound JC5, which also has a pair of input gain dials. Parasound recommends to set them to the max. That does seem to make the amp sound better when I was using my JC2 as the preamp. So I kept it that way.
I did try to dial back the JC5 input gains, and max out the SLP-05 gains. To me it sounds better with the JC5 at max, so I decided to dial down the SLP-05. Even at the 3 o'clock position, my max listening level rarely go past 10 o'clock on the volume control of the SLP-05.
Just thought I’d ad my two bits as I have a lot of experience with the SLP-05. I do not work for Cary Audio. First off avanti1960 is correct. The two “Balance” controls, essentially extra dual mono controls, can be turned down so you have plenty of range on the main volume control. If you want to be able to adjust the main volume control to 12 o’clock, then set it there and adjust the two balance controls until you find a comfortable level. This accomplishes the exact same thing as buying an external set of volume controls.
The main volume control in the SLP-05 is a motorized Alps Blue Velvet control. Fairly good controls. The other two balance controls are pretty cheap crap controls. And yes the quality of the controls will affect the sound quality. I know some people have wired past these two controls to get them out of the circuit and yes, it is noticeable. In the old days we used to be able to get the Tokyo KO-ON Denpa stepped attenuators which were fantastic and yes expensive! Khozmo now makes some really nice controls.
A poor quality control will add grain, noise and cause a loss of the overall clarity and smooth character of you sound, etc.
Another thing that can be done is to get the ultimate upgrade that Cary offers. One part of the upgrade is that they change the plate and cathode resistors which reduce the gain some and also improve the sound. There is a lot more done but this part is of interest to you. This upgrade is totally well worth it and dramatically improves the sound quality. I would also have them wire passed the two balance controls unless you really need them. Or purchase two really good controls and install them in place of the two inside the SLP-05. I don’t recall the value of the two but it is stamped on the casing of the controls. I know the main Alps is 100K.
Just like any part in the circuit or a cable, etc. The controls make a difference. Now whether your system can reveal that or you’re ears can hear that difference is where you draw the line on how far to go and how much to spend. Don’t forget, if you add external volume controls that also means more cables.
An attenuator **is** a volume control. So congratulations, now you have two :-)
Just turn down the volume. If its not tracking well, sure maybe you need to add fixed attenuation to get the volume control into its linear range (which is why i abandoned rotary volume pots a while ago).
4 resistors will do the trick, set up as voltage dividers. Simplest, least sonically detrimental approach possible. About 20 cents plus fabrication and whatever hardware you choose to use.
OK let me tell you my experience. I have a Pass Labs CA160.8 amp connected to an Audio Research pre with Avantgarde horn speakers (16 ohm). The gain matching was all wrong. You could not move the volume button past a certain level without the speakers being ear splitting. In addition the background noise was nearly as loud as the music. Purchased a set of attenuators. Problem solved. Great sound … volume back under control and all background noise gone. I bought Rothwell Attenuators on line. You can select the amount of attenuation you like (recall there are three choices/levels). Just buy these. Price is OK and believe me they work like a charm. Don’t cheap out to save $30 … these will likely be the least expensive bit of equipment you will have in your audio chain.
I would be careful with the channel volume control versus main volume. I had to carry 05 for many years, my understanding is that maxing out the individual volume controls put them out of the loop, allowing for a more transparent/better sound. I mainly used the main volume as the volume attenuator, I did not use the individual channel controls. I use a totally different preamp now, no issues with the gain.
"After reading through that revived SLP05 thread, it made me wonder and inquire if the same volume would sound better if I was obtaining it at a higher setting of the volume knob. In other words, would my desired volume have a better sonic quality if it was achieved with the volume knob set to twelve o-clock or more as opposed to nine o-clock."
The answer is likely no. By adding the attenuators you're adding another step in the signal chain. Most of us would agree that is a bad thing. Just paint a new indicator on the volume knob.
The reason for having a volume knob in it's "sweet spot" is that's attenuating, or altering, the signal the least possible. By adding in-line attenuators you're working counter to this.
Thank you again to all that have offered me input on this.
@twoleftears for the moment I will single out your reply as I can answer these questions with concrete answers:
There are two issues here, does the volume pot have an optimal operation range (typically around half way between min and max), and does the way the volume pot operates at the moment give you enough fine adjustability to hit exactly the volume that you want to listen at.
#1 That would be about twelve o-clock, and if I put it there with anything but low level recordings, it would be blasting me out of my small listening room. It would be LOUD.
#2 Yes, I can find a level that works for me, but it gets there quick. As previously typed, usually around nine o-clock with some + or - depending upon the level of the recording.
After reading through that revived SLP05 thread, it made me wonder and inquire if the same volume would sound better if I was obtaining it at a higher setting of the volume knob. In other words, would my desired volume have a better sonic quality if it was achieved with the volume knob set to twelve o-clock or more as opposed to nine o-clock.
@russ69when you say that an attenuator "will drive the preamp harder," is the bottom line that this is what I want to do to achieve (at least "on paper") better sonic quality?
I had a Bruce Moore preamp with dual Goldpoint stepped volume pots. Volume was either to loud or to low, was not enjoyable. I contacted Goldpoint and he walked me through how to add resistors. I ordered some Takman resistors and soldered them in and each step was not so drastic. I could now find the perfect volume setting. I don’t know if you can add resistors but you may be able to change out you volume pot.
I forgot the SLP has separate channel volume controls. I really don't think there is much difference between the main volume control and the individual volume controls. An attenuator on the other hand will drive the pre-amp harder, with less noise, and nearer the best operating range of the pre-amp. Not sure if it will sound better than just killing the volume balance knobs but on paper you would be operating in a better area.
I have that same problem with my AR ls28se. Using the dac I can only go to 10 or 12 on the control before its too loud. I'm running 4 mono blocks, 2 PL evo 400 and 2 PSA 700m amplifier. How could I incorporate this into my system?
the goal is the best sound possible for the preamp and amp system and let the volume control fall where it may.
in my case I started with the gain controls at max level and listened. the sound was to edgy, like a phono preamp with too much gain, even at moderate volume levels. it sounded slightly coarse, like you did not want to turn it up at all even beginning with low to moderate volume.
I then backed off the levels until the sound was smooth and lost the edginess- happened to be right about mid level.
it isn't about where the volume control lands, the gain controls adjust for the best sound though the volume range.
i started with them at the highest setting (1) so that I knew what too much gain sounded like and (2) backing off just enough to sweeten the sound and not too much to lose dynamics and drive.
FYI with digital sources volume at 9:00 is just starting to be fun, with vinyl the volume likes to be at 10:00 to 11:00.
adjust the gain for the best smoothest sound starting at the top level and the relative volume level will sort itself.
There are two issues here, does the volume pot have an optimal operation range (typically around half way between min and max), and does the way the volume pot operates at the moment give you enough fine adjustability to hit exactly the volume that you want to listen at.
Experiment with the trim levels and see if yo can hear a difference.
@avanti1960again, I want to stress that I am not disagreeing or seeking an argument. Only seeking clarification on this subject. So if I use the left & right "input level" pots to control my volume, is that a better thing than using the big knob (labeled 'listening level") to accomplish my volume control? I wouldn't be simply robbing Peter to pay Paul?
And to do this, what would you recommend? Start with the big knob at 12 o-clock with the left & right "input level" pots backed all the way off and then advance them judiciously?
Thanks russ69. I have zero noise issues with any of my equipment. I'm pretty good at that part. I had my C20 done by Samra @ oldhvymec's suggestion. That was the best money I ever spent.
The Cary I'm babysitting for OHM. It came in as he went out. I have my own, too. His is original no modifications. I get to side by side the two. One has all the goodies, one is stone stock.. It's kind of fun. Neither are as good as Samra's C20, that is the absolute BOMB. It works with anything and is tough as nails.. I hate the old analog pots, BUT it is the biggest part of it's charm also.
Save some money go to Parts Express Harrison Labs has Attenuator's for about a third of the price. I used the 6db version on my Audio Research SP-16 years ago. Worked like a charm.
The only problem with to much gain is floor noise usually. If you have high gain and sensitive speakers it can be VERY noisy with certain media. I use a C20 Mac that has so much gain you have to be VERY careful. It is also one of the quietest preamps I've used. It took a few years to get there but it is black as night compared to any preamp. BTW I have a SLP-05. I just started fixing that mess. It sounds great and looks great, it still has a ways to go to catch that C20 though. I'm having a real tough time with no tone control. I'm glad I have a bass management system that is independent of preamp. Sure is pretty though. RED body black faceplate.
This is where volume control quality comes into play. Cheaper potentiometers will often be poorly matched between Left / Right channels especially at lower volume levels. The ubiquitous Alps RK27 is OK but maybe not great here, at least when you get up to the level of that Cary (I don’t know what the Cary uses, but there’s a good chance it’s this). This is why the insane Alps RK50 goes for such a premium. If you open it up the Alps RK27 is easily recognizable by its sandwich of 2 or 4 navy blue plastic "gangs" (they used to call this part "Blue Velvet") and a metal can motor & controller at the end (optional for remote volume control). The RK50 is a huge beautiful cylindrical brass beast (it won’t be this) and requires an external motor rig with belt drive to be remote controlled.
On the flip side a good stepped attenuator is utterly transparent sounding and well matched at all levels, but the steps themselves are too big on the lower end of its scale so it can be impossible to find the "right" volume when you have too much gain.
Digital volume controls give good matching and good granularity, but some will claim they don’t sound as good as the other 2 types.
Besides channel matching, the other problem with high gain preamps is that your music signal will be riding closer to the noise floor anytime you’re not utilizing most of its gain. So you’re much more likely to hear a hissss noise floor. The suggested attenuators will help BOTH your channel matching and signal to noise ratio.
The problem with some tube preamps is that it’s very easy to provide "way too much" gain for use with modern digital sources, with many tube circuits. Look at some of 1970s/80s ARC/ CJ tube preamps with ludicrous 20dB+ gains and 12AX7 tubes - this was before the digital age really took hold. Most balanced DACs push out 4 Volts. That’s way more than required to slam most amps well into clipping without ANY added gain from a line stage.
@voodooloungethis is strictly a question, not a question looking for an argument.
Why is a lot of gain necessarily bad? Does having more "real estate" (as I have hear it referred to) to utilize on the volume knob improve the sonic quality?
I'm having the same problem with a new addition. Volume hoovers around 9-10 o'clock. My turntable level is fine, it's the digital source that needs to be tamed. I ordered Rothwell attenuators and hopefully they will help without effecting sound quality.
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