I have never heard a tube amp that didn't buzz when your ear is at the tweeter. It is normal.
Having said that, you may get an overall improvement in sound with a regenerator but since the amp is downstream, it still won't help its noise floor. Just my guess.
Arthur |
I use regenerated power on my sources for two reasons. 1- its too expensive too regenerate for my big amps. Also regenerators have limiters to protect them. So if your regenerator is rated at X then make sure your amp will never use more than 60-70% of X. I use a P-300 on my sources and could never do without it. If the power goes off and it resets its output to 60 HZ I can hear it right away. My setup loves the 120HZ setting. BUT don't buy a regenerator to try and solve your noise issue, buy one to make your system sound better. Tube amps will make a little noise audible from close to the speaker. Not audible while listening to music or in the listening position. My last point is that if you do regenerate it is better to start with the sources anyway and do the power amp last.
ET |
Interesting system. I'd agree with Aball, except the kind of buzz he's talking about usually remains pretty much constant regardless of volume setting -- especially since you have a ss preamp. (A nice combo with the Mesa BTW) So you may have some very low level tube buzz, but there may be more coming frome something else. I'd need to know more about how your system is hooked up. (It's unlikely, but maybe the exploded crossover networks dribbling across your floor are picking up some RFI, ha, ha!)
1.) You shouldn't need a regenerator if you have ded. circuits AND your utility company supplies reasonably uniform power, both cycle and voltage. Uniform voltage is especially important for tube amps, unless they have auto-biasing.
2.) Always UNPLUG the system when thunderstorms approach. Just tripping the breakers doesn't always work, and NO regenerator or (ugh!) conditioner, can protect you.
3.) Since you are running digital gear, it could be putting digital "hash" back into the power line and into your preamp -- even when it's turned 'off') Try unplugging the 850 and see if it helps. And in any case, make sure you are uning a quality PC with a floating shield on your 850, AND
3a.) You might want to consider a balanced power unit like the ExactPower SP-15A or one of the BPT units for your front end stuff (and they have digitally filtered outlets built-in for the 850) That would be the finishing touch IMO -- but I don't really think you need a regenerator when you already have ded. circuits.
. |
I had a buzz in my Barons which didn't entirely go away when I used the Barons ground lifters (BTW - if you haven't already done so, try lifting only one ground, alternating channel to channel, that might help). Mine went dead quiet when I plugged them into a seperate dedicated line and an old power filter made by Power Wedge especially for amps but I never did get rid of a buzz when the amp was in pure pentode mode - should have sent the thing back to Mesa.
Art, You've got to get out more. At least on my 91db speakers I have 2 tube ams which don't buzz at all - ear next to the tweeter. I've got 2 tube and one SS that do, not counting the MB which I no longer use. :-) |
Nsgarch.....those items on the floor are mouse traps. Actually there are less of them now than there was when I took those pictures :) Currently, my amp and cd player (with VH Audio Oyiade shielded cable) are in the 20A circuit. VPI, phono stage, and active Synergistic speaker cables and interconnects, are plugged into an Isobar which is plugged into the 15A circuit. I think my power is pretty good.....my house is served by it's own transformer since I'm off the road a bit. My main thing was whether or not the Mesa would benefit from any conditioning or regeneration......or if it is actually detrimental with a tube amp. So, Electroid, you can feed 115V and 120Hz to a cd player and it likes it? |
So I'll bet the mice are laughing at you too!
If you MUST use a regenerator, get an ExactPower. They don't work the way the (lowish output) P-300 and others do (which is to throw away the whole AC signal and re-build it). Consequently, the ExactPower can offer 1650 watts from 120V wall current, more than enough to power your entire system. But I still don't think you need one.
Conditioners (any kind/brand) are old technology and bad for sonics. STAY AWAY!
After looking at your system again, I would recommend you plug the amp directly into the the 20A circuit all by itself, and get a used ExactPower SP-15A balanced power unit (plugged into the 15A circuit) for everything else.
. |
A bit of news. The little buzz is only when the preamp is on phono, and the phono stage is turned on. Preamp on CD = dead quiet. Ground switches on the amp don't seem to have much effect. So the VPI is grounded with a wire to the ground on the phono stage.....is that good or bad. |
I don't know enough about the VPI chassis to really advise you. Typically, the tonearm leads have five connections: two signal leads (from cartridge left and right) which each consist of a hot and ground conductor, covered by a braided shield connected (along with the ground conductor) to the "ring" of the RCA connector at the phono preamp end. In addition, there is usually a black ground wire bundled with the two RCA signal leads that you connect to the ground lug on the phono preamp. This wire goes into the tonearm and is usually connected to the armwand (if it's metal) in order to shield the internal signal wires inside the tonearm.
If the TT chassis is electrically connected to the tonearm, that should be enough, but if it's separate, then you should run another wire from the TT chassis to the phono preamp ground lug.
What kind of tonearm, cartridge, and tonearm cables are you using, and how do the tonearm cables connect to the tonearm?
. |
My apologies, this thread is moving in two directions now. Nsgarch, the table is a VPI Scoutmaster with a thick, I believe, mdf chassis. Cartridge is a Clearaudio Virtuoso Wood. The head leads go to a junction box separate from the tonearm where the cables and ground are attached. interconnect is Synergistic Looking Glass. Amazingly, the VPI setup says nothing about grounding. It does say to try a shielded a/v interconnect, if there is hum. Don't wanna do that. I am going to read up on Exactpower, although they are sorta expensive. |
I think the Synergistic ICs may be the problem. Are you using the active shielding? Is the active shielding connection at the preamp end or the TT end? (might try reversing it). If that doesnt help, try a pair of regular ICs just for comparison (with the arrows pointed toward the preamp)
I don't think you need to worry about grounding the VPI chassis, which is why the don't mention it.
. |
It is not normal for a tube system to buzz. Some hiss is normal and maybe a bit of hum but buzzing is not.
Glad to see you have isolated the problem to the phono. Now the hunt is on. Try moving cables around to see if the buzz changes, try it without the turntable plugged into the phono stage to see if it is coming from the phono satge or the table, try grounding the turntable to the phono stage, try it without, try grounding the turntable to the preamp, try different interconnects, try moving the phono stage and turntable, try turning off other things in your house like dimmers and appliances.
You get the idea. There is no universal solution so you just have to keep trying things until you get rid of it.
When I first hooked up my latest phono stage the hum was as loud as the music. After trying umpteen different combinations of things you now have to stick your head in the horn to hear anything.
I am using a power regenerator for the high voltage supplies in my integrated and for my phono stage. It does make it a bit quieter but the main reason I use it is my integrated bias is sensitive to changes in line voltage. For your system it may not make any difference. |
Yup, can of worms. It definately has something to do with the active shielded cables, which are new to my system, btw. Turning off the switch to all the shielded cables makes a big difference. I have a non-active Looking Glass from TT to phono stage, and an active from phono stage to preamp. I switched those and it made it worse. I need to experiment some more. Herman, thanks for the input......what I have is a small buzz/hum at a very high listening level, with no music playing. it's annoying, but I can not hear it from my chair. |
Here's the thing. Can't use active cables anywhere in the phono area. I don't know if that is normal, but with that active cable from phono stage to preamp replaced, and the shielding on for everything else, the hum is very small....and I would never listen at that high volume level. I'm a little confused about active shielding now and in saying that I have probably highjacked my own thread for the third time. Thanks for the ideas though.....I was not even thinking about the cables, obviously......I was thinking about power regenerators. |
I love regeneration for sources and as I said wouldn't do it w/power amps. I reread your post. Do you get the hum through the spk w/ only the power amp on or when the pre is on and is set to phono? Thats a minimum of four gain stages if the latter and you will hear a little hum. Especially due to all gain needed for a phono cart. Back to your 120HZ question - it is wonderful and I have not met a piece of gear that can't handle it......unless you have an older TT w/ an AC motor that gets it speed calibration fron the AC frequency. As to N's comment on the lowish power output P-300(300 watts max, I never use but 60-70%of it as I said) it was made to drive sources not big amps. They had a 600watt and 1200watt for larger draw gear. Often a pre,phono,CDP and tuner wont draw but 100 to 200 watts total. In fact the process of turning the AC into DC, cleaning it and then turning it back into AC is what makes it so good. Then setting it to pulse 120 times/sec instead of 60.....well judge for yourself. Don't take our word for it, find a dealer that loans gear for home demo before you buy.
ET |
Think about what you are trying to achieve, which is great sound at your listening position. If you can't hear it at all from your seat, and it otherwise sounds as you wish, leave it alone.
If you stick your head in the corner of the room you will hear boomy bass but nobody considers that to be a problem since it sounds fine at the sweet spot. Why does a slight amount of noise that can only be heard near the speakers bother people so much?
There are ways to make a system completely quiet but at the expense of performance. A system that doesn't have any noise at all when you are close to the speakers is probably pretty lifeless anyway.
IMHO you are chasing ghosts. |
I'm good. The little hum (only with preamp set to phono and the volume cranked) is a not a problem. I will not be buying a big power regenerator in order to service my amp. That was the reason I asked my initial question. I will most likely find a way to try out a PS 300. Can't justify the price of a big one for just front end. Looked at your systems.....very impressive, especially those horns and that phono preamp. Wish I could hear a bunch of the systems I see on here. Thanks for your help...... |
So the buzz was a hum? That is what I had assumed. Sounds like it's due to high gain needed for phono. I would like to know if the regenerator reduces it. Otherwise, lower gain amps and/or lower sensitivity tweeters can reduce the noise to the point of making it inaudible. That is the trick since you will always have a noise floor to deal with.
Arthur |
My experience has been to try a Audiophile APS with two Richard Gray power companys plugged into one each of the outlets on the rear of the Audiophile APS with components plugged into the Richard Gray power companys and this has made a tremendous impact on the noise floor and the musicality of the overall presentation.First, suggested by a friend and I haven't looked back since.
Chuckie |
Arthur.....I just reread all of this. I wouldn't mind keeping this discussion going. What Nsgarch said at the beginning is probably what I now have. A low level hum/buzz with the volume cranked, and the preamp set to phono. I hear it in the mid and the woofer more so than in the tweeter. It's not much, but it is much if I plug in the active shielding on a Synergistic Looking Glass interconnect that runs from phono stage (Musical Fidelity LP3) to Levinson preamp. I wish I had known that active shields don't work in the analog area, since I purchased that IC recently. If things remain the same, I will eventually change those ICs. Always wanted Music Groove anyway :) And then back to regen power. I would invest in say, a P-300, if it did nothing more than improve the performance of my Wadia and my preamp 1 percent. If I could hear even a small improvement in vocals, or timbre, or soundstage, I would consider that a bargain. I would love to know if any or all of you use regulated power for your analog equipment.....turntable and phono stage. I have thought about the VPI SDS power supply also. I try to make good decisions mostly based on the input I get from right here on Agon. I don't have a local 2-channel high end store anywhere near, so I rarely try things out. Whoever in here said that your performance is only as good as the weakest link in your system, I think was right on. I recently took one of the mouse traps off my floor (I fine tune crossovers outside the box using some cheap hookup wire to run into the box), and installed it in my bass cabinet. Soldered it point to point with Kimber wire and Cardas copper binding posts. The improvement in bass response is quite something....deeper, tighter, and with snap....it's there and it's gone....quick. Probably an extreme example, but it was a lesson for me. No more testing with cheap hook up wire and what else in my system is weak. And so I talk too much? |
Look, Racer, I'll go out on a limb and repeat myself:
1.) Forget a regenerator. You don't need one with good ded circuits and good utility service. Plug your amp into the (20A) wall.
2.) Forget power conditioners. Old technology. If you don't believe me, read PS Audio's blurb on their PS-300 webpage.
3.) If you want to do something more for your sources, get a balanced power unit from either Equi=tech, ExactPower, or Balanced Power Technologies. Do your homework and decide which one you like best. I won't make a recommendation, except to say you won't need a megawatt sized one for just the front end stuff (since your amp won't benefit from balanced power as much as just a good ded circuit.)
4.) Do get some tonearm cables made for that purpose. In order of performance (IMO and ones I'm familiar with of course) Siltech, Purist Venustas, Silver Breeze, Hovland Music Groove, Cardas Golden Reference.
5.) Get the same make/model ICs from phono preamp to preamp as the TA cables. Synergy is a good thing in this application (I didn't realize your ML 38 didn't have built-in phono.)
. |
A little late to the dance on this one, but my 2 cents. I am in agreement with Nsgarch, somewhat. The difference from what Nsgarch said, I plug my amps into a simple filter. It is a non current limiting filter, I feel I get some benefit from the filter at a very small cost.
As far as an active power conditioner, I used PS Audio's P600 for my Audio system several years ago. I had a Cary V12 power amp at the time. When plugging the amp into the 600 and using any of the Multi-wave setting, I would get mechanical hum from the output transformers on the V12. This did not occur when using a straight sine wave setting. After talking to Denice from Cary, and, reading all I could at the time, this is not an uncommon phenomenon. Denice said as well as PS Audio's web site, this did not hurt the amp in anyway, but I decided not to run the amp through the P600 anyway. It was caused from the metal laminates vibrating on the transformers. The P600 now was used only for the front end of the system, a little over-kill, a P300 would have worked just fine for this application, I sold the 600 and bought a 300 and used this setup for 4+ years. About 2 years ago a friend of mine started reading about these passive balanced power conditioners. He bought a Blue Circle MR800 and brought it over for a listen. It was as good as the P300 but without the heat and power usage. I sold the P300 and bought the Blue Circle MR1200 thinking I could now use it for the Power amp as well as the front end. This worked great until now when I decided to actively bi-amp. I guess my point is as far as the amp goes, buy a simple non current limiting filter, I am using the Welbourn filter, cost $150.00 6 months ago. You do have to assemble it but is kind of fun and cost effective. The PS Audio's Ultimate Outlet would also work very well, a lot more money new and a little more money used. The good news about buying this piece used, these devises don't have anything that could be worn over time.
As Nsgarch says, a good passive balanced power conditioner (I might ad Blue Circle's name to his short list of passive conditions), the difference from his point of view, use it for the whole system front end and the amp, just make sure that your wattage used is not more than the power conditioners rated output by quite a bit. You need to allow for added short term power from your amp, a whole other issue. Or, a balanced power conditioner for the front end and a filter for the amps. As I stated earlier, this is just a 2 cent opinion and only a 2 cent opinion.
Oh, don't forget to use good power cords, this maybe is the best performance improvement regarding power supply...........Bob |
I use an MIT passive filter in the form of the "Z-Strip" and I noticed a rather obvious improvement in noise floor reduction. I recommend it based on several experiments where I would add it and then remove it to see the difference. It works consistently with everything. But I haven't tried any others so.... My audio buddies use the PS Audio Ultimate Outlets and got similar results.
My reservation about power regenerators is that many times, more noise comes from the stereo components than the incoming power. I have seen this MANY times testing electronic equipment in my lab. You can even see the results that the rat's nest of cables can bring on - by jiggling the cables, you can see the noise level change on an oscilloscope. It is interesting and scary at the same time. A regenerator won't make a bit of difference here since the noise is injected downstream of it.
However, it is unclear as to whether your problem is the incoming power or your amps. At very high gain, everything is amplified and there is no way to know what is the cause without experimenting. If the regenerator lowers your noise floor, then the problem was your power. If not, it is your amps. I am inclined to believe it is the residual noise floor of your amps you are hearing.
Since the noise isn't really coming from your tweeter, I suspect you may be hearing spurious noise from your power supply in 60 and/or 120Hz form. Only that frequency range would be audible from your woofers and mids. The noise I was talking about before is much higher in frequency and so is only heard in the tweeter. I don't think any regenerator is going to solve this problem but passive filtering might. Let us know what you find out!
Arthur |
I almost always agree with Nsgarsh,but I'm not sure about this latest thought.For me,regenerated power has a distinctive advantage.
I have a dedicated room,with three dedicated lines.I recently had a new,quality circuit breaker box installed,in basement.Nice Improvement!!I added PS Audio ultimate outlets to my front end stuff,after hearing them(CD/LP/Pre/phono),with my amp plugged into a UPC 200.All were superior to wall,and previous passive stuff.THEN I got a PS Audio P-500 for my front end stuff.I have amps on another line and don't want to pull everything from one outlet,so they will not be run from regenerated a/c("drats").The difference with the P-500,only on pre/phonostage,CD player,turntable,was DRAMATIC.Obviously way beyond the very good Ultimate outlets.Not close,actually.I don't know,for sure,if it is the "balanced power" or the perfect regenerated sine wave.Probably both.BUT I can now,not live without this.The business of eaking itsy bitsy tweaks in other areas,like the latest cone,or shelf,though very important,pales by comparison.
My conclusion is anyone NOT running a well thought out "power management system" has not heard what their stuff can do.I was surprised myself,and remember,I had three superb dedicated lines,and went through a good amount of passive filter/conditioners too.
One thing though....Now that I have become SO smitten,with an area of the hobby that I really knew little about(thinking passive,non-balanced or regenerated devices were enough),I have "gone to town" trying to gain as much info as possible,in an effort to truly get a grip on this stuff.For now,even with some of the newer hoity toity regenerators about to come out,there is still the issue of heat,AND do you really want to pull ALL of the system's power from one wall outlet(even the wiring,in the wall can limit power,and add resistence,so I've read).One reason why I split up my front end and amp electrical sources.
Yet,that being said(and no guarantee of being an issue for many)based on what I have read,recently,I would love to run my system on an Exact Power Ep-15a,coupled with the NEW Exact Power Ultra Clean unit!!Though pricey,it is less money than many of the high quality cartridges so many of us talk about,and with very little heat dissapation,AND balanced,essentially regenerated power,the whole system can be run.TO THE NINES!!I can only imagine how great an improvement this configuration can make.There is a new unit,sold by Bryston(the Torus) which has HUGE oversized transformers,made by Plitron,which does NOT regenerate,yet is balanced,and probably stores a TON of energy.It is supposed to be fantastic!Three thousand US dollars.This is a nice "one box" alternative to the magnificent "Exact Power EP-15a/Ultra Clean" two box set-up,and cheaper than that combo.Yet,so few advanced hobbyists are actually aware of this aspect of line maintenance.I was not,and have some very high brow friends who would rather eat nails,than put anything between their components,and their "dirty" outlets.
But they have no problems upgrading to four to five thousand dollar cartridges,or spending big bucks for great NOS tubes.BTW,if I had not already bought my P-500,my tastes would run to the Exact Power combo.But it's too late now.I saved alot of money,but when it comes to this hobby,I usually opt for the better configured product.Too bad I was clueless,only two weeks ago!
Best! |
Sorry!Forgot to mention that I don't play around with the different waveform settings,on my P-500.Set for 60 hz/117 volts continuos.The "System Clean" demag feature seems cute,but I simply use it,and have not bothered to A/B it.A SIN,but it is SO over the top good,that I don't care. |
Ok, one thing is for sure, all of you people can type better than I can! This has been an education for me. I had no idea most of the equipment discussed here even existed. Thanks for sharing your experience, and expertise, everyone. I'm now convinced that doing SOMETHING with power is much more than a tweek, and that is true even if my ac is not overly "dirty". I have a long way to go. Only two weeks ago, I ran the dedicated line to my tube amp. A month ago I was replacing all my cables with Synergistic Resolution Ref. I still have unshielded power cables in my system. I now have a very good idea what is next......I'm feeling a big lean in the direction of an SP15A, once my wallet recovers from the cables. Last winter I put V-Caps in the Mesa. It's what is so much fun about this hobby......listening to music that sounds somehow better than it did before. |
