Using a Variac to power amp your CJ amp

[roberto]

When I said walking speakers was not literal. The noise is heard when the capacitors are getting charged, The noise is odd and it is harmless to the woofers.

With a good quality speaker switch he can solve the problem. Turning off the speaker switch, power on the amps, there wait 10 seconds and connect the speakers: problem solved.

Happy listening!

[MLAS]

All the caps in all the amplifiers are new.
I know that using a Variac is a no go for many highend audio aficionados, but I never hear why.
As said I do not hear any difference with or without a Variac in my AC circuit in front of the amps.
I've got this idea from a friend who has been working in highend audiostores the better part of his life and he started his 8 Levinson ML-2's on a Levinson HQD system, always with a Variac. The tripping of my Computersystem UPS when starting the CJ PREM One was just an example that the starting of a poweramp could trigger this reaction. My CJ has 6 brand new caps four 4700uF and two smaller 2200uF 450 Volt rating filtercaps running each at a B+ of 560V/2 (Parallel configuration) 280 Volts. That is to my knowledge is W = 1/2 C U2: 1/2 times 0.0232 (F) times 280X280 Volts = 909 Joules.
My Thresholds pack 400,000 uF each at a railvoltage of 75 Volts and that equates to 1/2 times 0.4 (F) times 75X75 Volts = 1125 Joules.
Same is true for my CJ EVO 2000, 1125 Joules of of energy stored.
So the the energy to load those powersupplies is virtual the same and I do not see why the tube amp is any different than the SS/hybrid amps for that matter?

But I got what I asked for from you all, that is opinions on this matter and I wish to thank you all for that because I do appreciate all (dissenting) opinions
I'm open for discussion and eager to learn.

Thanks Robert

[roberto]

Hartley/Quads/Decca.. i remember that system. When I was entering into the high end systems, in the late of the 80s...one woofer, two midrange and a tweeter for each speaker. Also remember the Mark Levinson Reel to Reel tape deck playing at 30 ips., two tracks.

Well, the final: your ears, your money and your system.

Happy listening!

[MLAS]

Hartley/Quads/Decca.. i remember that system. When I was entering into the high end systems, in the late of the 80s...one woofer, two midrange and a tweeter for each speaker. Also remember the Mark Levinson Reel to Reel tape deck playing at 30 ips., two tracks.

Well, the final: your ears, your money and your system.

Happy listening!

That was the ML-5/5A basically a Studer A80 with in- and output modules from Levinson.
The guy I know has around 40 Levinson units and the heart of his system constitutes of the HQD System wit 8 ML-2 Class A amps.
As said he started his 8 ML-2's with a Variac feeding I believe Tice Power Block Line Conditioner with Titan Power Supply connected after the Variac.
In another room he has a Levinson ML-7/ML-3 feeding the Infinity QLS.

Love to hear some technical cons against the use of a Variac

[AnotherJohnson]

As said I do not hear any difference with or without a Variac in my AC circuit in front of the amps.

To me, that says it all.

You believe the variac approach is unobtrusively helping you with a problem most do not have. To you, it is sonically transparent, and who can argue?

I think it is harmless, and if it really helps your other problem, or extends tube life in some way, that’s great!

I would not advise you to abandon the variac. At the same time, I feel no urge to trot mine over to the audio system. There’s no problem there to solve.

[MLAS]

To me, that says it all.
You believe the variac approach is unobtrusively helping you with a problem most do not have. To you, it is sonically transparent, and who can argue?
I think it is harmless, and if it really helps your other problem, or extends tube life in some way, that’s great!
I would not advise you to abandon the variac. At the same time, I feel no urge to trot mine over to the audio system. There’s no problem there to solve.

Clear reasoning indeed!

[Big Dog RJ]

Yes, agreed on that as well.

Mlas; As I mentioned before, focus on your system... obviously learning from others config also helps to derive possible solutions, as is the case with your mate who's running Levinson amps with this unit. Since his doesn't seem to encounter any issues, perhaps means all is well.

Asking for our opinions/ advice is a good approach, simply because you care about your system and want the best for it, so we tread cautiously... good thinking!

If I missed it, I'm wondering whether or not I read somewhere in your earlier posts that you may have asked JF about this... Just wondering if you received any feedback from him or anyone from CJ? Or have I got it wrong...

I'm sure you'll figure out a way and make sure it's the right solution for your particular system.

Speaking of "right solution" when I was using that aluminum disc mat from Spec on my TT rig, it was causing major static issues. I received various suggestions and advice, which were all great! To some effect I managed to discharge the static from myself before changing LP's, by touching the QX4 unit first. Helped tremendously, best advice. However, the metal disc mat just didn't work no matter what I tried, grounding this and that, so I no longer use it! It's now tucked away in its sleeve waiting to be passed on to another good mate, who just happened to purchase his new power amp, the Classic 62se to drive his SF speakers. Hopefully he wouldn't have a problem with the Spec mat and at least I'll be happy knowing that someone else is enjoying their fine tunes!

Cheers Mlas, hope it works out. Let us know how it goes.
Best, RJ

[MLAS]

I did not ask Jef Fischel or anyone at CJ about this. They seem to be very busy indeed because I asked them some simple questions like:
- Where can I buy that long red plastic rod to adjust my bias without the need to unscrew the whole meshcover...
Over here I can't find it that's why I bothered them. Got that piece of handy tool with my pair of Fives so that's why I know about it's existence.

- How can I prevent a catastrophic outputtube failure that causes more damage than only the (relatively expensive) B+ Bussman fuses and/or cathode resistors?

Got no answer at all...

Should have asked them on this Forum first of course

https://drive.google.com/file/d/1nPUNo3 ... sp=sharing

This is the Variac I'm gonna use probably:
https://drive.google.com/file/d/1MSPu8I ... sp=sharing

[Big Dog RJ]

Wow! Nice one matey.

I'm always fascinated by how majestic CJ's classic mighty power amplifiers used to be. Up against the other one, the Threshold looks like a toy... although it's certainly not!

Looks like you've managed to figure out a pretty good solution to support your system. See how it goes, if it works and all is well then that's all that matters.

Cheers, and do enjoy those fine tunes!
RJ

[MLAS]

Thanks.
Always great to hear from 'Down Under'.

Yes I certainly enjoy those Thresholds (34 kilogram per chassis so no wimps indeed) on the duo woofers but no good on the mid/high section of my Infinity's.
Premier One (B) is needed to let that part sing.

[MLAS]

Thank you Uncle Doug:
https://www.youtube.com/watch?v=n3mxbewxNIM

So even with a rectifier tube you can use a Variac wisely with old tube equipment.
I'm not saying or extrapolating that a Variac is therefore wise the use every time you start up your audio rig but it;s at least a useful tool to comparatively safe start up barn finds from the Sixties...

I've cleaned my Philips 23A Variac, tighten all the screws and lubricate the axelrod put a Kemp DC Xterminator in front of it and it is more silent than my CJ PREM One AC Xformer which is a big humming when cold, Northlake C126-139.

[MLAS]

So it could be even come in handy starting the Prem One B (besides the Thresholds) and first power up the auxiliary circuits like the heaters, bias and so forth and when you crank up ten VAC the B+ comes at last at full strength. I'm just expressing my gutfeelings not a scientific opinion.

[AnotherJohnson]

Not arguing. Just thinking out loud.

It could be that the variac could sustain/extend life of some no longer availability parts, by reducing the transient stress of start up. It’s a point that is hard to argue against.

If the goal is to curate and preserve old components, that’s cool. But I have to wonder if parts that need this very gentle treatment sound anything like they sounded in their glory days. Note that I “wonder.” I’m not saying unequivocally that they don’t.

I do say that, in my experience, and with my listening goals, there have been real advances as each new generation has been introduced.

I went through some of this with golden age McIntosh tube gear during the 80’s. I was really focused on preservation, and very happy with things like the C22 and Mc240’s.

I loved the nostalgia and considered curation a worthy objective. But eventually, when faced with the clear sonic superiority of the new tube gear coming along, I shifted my goals to better support the quest for sonic Nirvana. It was unachievable with the old gear in direct comparison to the best new.

Obviously YMMV.

[roberto]

I did not ask Jef Fischel or anyone at CJ about this. They seem to be very busy indeed because I asked them some simple questions like:
- Where can I buy that long red plastic rod to adjust my bias without the need to unscrew the whole meshcover...
Over here I can't find it that's why I bothered them. Got that piece of handy tool with my pair of Fives so that's why I know about it's existence.

- How can I prevent a catastrophic outputtube failure that causes more damage than only the (relatively expensive) B+ Bussman fuses and/or cathode resistors?

Got no answer at all...

Should have asked them on this Forum first of course

https://drive.google.com/file/d/1nPUNo3 ... sp=sharing

This is the Variac I'm gonna use probably:
https://drive.google.com/file/d/1MSPu8I ... sp=sharing

Mlas, the plastic red screwdriver is made of fiberglass. I lost mine too. What I did is with a thermo-active sleeve, I isolated a metal flat screw driver, letting to have the enough tip to drive the slotted of the screw and works beautiful. Knowing that you like electronics, this could be an easy way to make your tool.

Great to know that you are happy with the variac, and seeing that it is a big variac, I don't find any problem to use it to solve your problem. It is a clever idea to do it. Usually, the general varian are mickey mouse type. The one that you have is BIG!.

Happy listening!

[MLAS]

Not arguing. Just thinking out loud.

It could be that the variac could sustain/extend life of some no longer availability parts, by reducing the transient stress of start up. It’s a point that is hard to argue against.

If the goal is to curate and preserve old components, that’s cool. But I have to wonder if parts that need this very gentle treatment sound anything like they sounded in their glory days. Note that I “wonder.” I’m not saying unequivocally that they don’t.

I do say that, in my experience, and with my listening goals, there have been real advances as each new generation has been introduced.

I went through some of this with golden age McIntosh tube gear during the 80’s. I was really focused on preservation, and very happy with things like the C22 and Mc240’s.

I loved the nostalgia and considered curation a worthy objective. But eventually, when faced with the clear sonic superiority of the new tube gear coming along, I shifted my goals to better support the quest for sonic Nirvana. It was unachievable with the old gear in direct comparison to the best new.

Obviously YMMV.

Good point also. You have to have the will and resources though to invest in those modern tubegear offers but I do certainly not advocate that refurbishing old stuff like: "they don't make it anymore like that", is the way to go. If you have the means you can explore and experience the current 'State of the Art' and I'm curious what that brought to you.
The Premier One I have was touted by the late Harry Pearson of The Absolute Sound, as the best amplifier ever, in September 1992 (Vol. 7, No. 27). The also late J. Gordon Holt pointed out in 1983 (Vol. 6 No.5 Stereophile) later that although this was certainly a good amplifier, a Rolls Royce, there is no such thing as the best. Nothing exists in a vacuum he stated and it depends also on the used other gear. Rationally speak-en he was certainly right and we're now also 40 years ahead with such things as R&D, probably better components and better manufacturing equipment.
Thanks for your sharing!

[MLAS]

Mlas, the plastic red screwdriver is made of fiberglass. I lost mine too. What I did is with a thermo-active sleeve, I isolated a metal flat screw driver, letting to have the enough tip to drive the slotted of the screw and works beautiful. Knowing that you like electronics, this could be an easy way to make your tool.

Thanks for the tip. What's a thermo-active sleeve and where can I get such a long screwdriver. I did searche for a solution along that way but had to give up...

Great to know that you are happy with the variac, and seeing that it is a big variac, I don't find any problem to use it to solve your problem. It is a clever idea to do it. Usually, the general varian are mickey mouse type. The one that you have is BIG!.

Happy listening!

I have two big Variacs now. A German Philips a 23A and an American brand new PowerStat 1256DU 28A which I'm gonna try to convert to a 1256DT version by my self.
The best (probably the most silent that's why I serviced yesterday my old Philips to run it at his best for comparison with the American behemoth) I'm gonna keep. Don't need two of those backbreaking units

[roberto]

Hola Mlas,

Here is the shrink sleeves. With the help of a hair dryer you are done with it!

https://www.amazon.com/625pcs-Shrink-Tu ... NrPXRydWU=

The ph2 tip flat blade screw driver:

https://www.amazon.com/dp/B0946X9JW5/re ... in_2_title


The shrinking sleeve you can find the right size too. The shrinking is about 50% to match the screw driver thickness. Also there are isolated screw driver blades too.

You can use three or four shrinking sleeveless to cover the desired length of the screw driver. The bias chassis hole is wider enough. You can find the ph2 size point flat blade in a hardware store, including the shrinking tube and the right size for the screw driver. I just showed to you what's the shrinking tube.

[MLAS]

Super Thanks for your effort highly appreciated.

[admin]

Although you can use a hair drier, I would highly recommend getting a heat gun. You can get one for under $10 at Harbor Freight. It makes heat shrinking a lot easier as you can focus the air and make it a lot hotter than a hair drier. They also usually include some nozzle attachments which come in handy depending on project.

[MLAS]

Thanks Admin.
Will use a heatgun anyway.

I know you sold you EVO 2000 but do you still have CJ fullrange tube amps?