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New to tubes


RockOn4Klipsch

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I recently purchased a Blueberry and VRDs from a fellow forum member, Silversport.

I've been reading about various tubes and their sound characteristics.

I continue to have some questions, substitution and where would you start your upgrade path of replacing tubes?

Substitution , first, Craig mentions that some Tubes choices require a 5u4gb rectifier tube, which tube choices require this change? Is this only dependent on output tubes , or does the driver and phase inverter influence the rectifier choice?

Could one simply choose the 5u4gb rectifier and continue to use kt88/90 and EL 34/84 ?

Next, if you were to start an upgrade of tubes , for both pre-amp and amp , where would you start?

It seems from my reading that the phase inverter may be the most important tube followed by Valve 1, would most of you agree with this, which would lead me to assume that this would be the start of replacing tubes.

Would you start in the amp or the preamp with tube selection?

Should one be inclined to search out tubes for personal sound characteristics and place these in the preamp section to mould your personal preferences and then send it to the amp with a more neutral tube selection? Or vice versa?

My concern with following with personal taste from preamp to amp may end up with too much of a good thing, so I was thinking of striking a balance between warm, fun, musical and detail but not too analytical.

I did kind of go through a wish list of new tubes all at once, this way isn't going to happen for a little while as I spent my fun money on these items. I can however pick and choose every month and want to make sure I'm going in the right direction.

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Craig is very cool to people that purchase his amps second (third, etc) hand. You are part of the family, and he knows best.

 

The output tubes determines the rectifier, and I do not think you would want to use 5U4GB Rectifiers with KT88's. I think this just lowers the plate voltage for the lower watt tubes.

 

Rolling is FUN in the VRD's, but do listen to them for awhile, and tell us what you think you would like more or less of, and we can point you in the right direction.

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There's nothing glaringly wrong with the sound, maybe a little more sizzle on the top than I expected, with cymbals and sibilance at higher listening levels.

That being said , I wanted to start with a fresh set of tubes to give everything a fair chance at what it should sound like.

Bill told me the items had been gone through by their respective creators in 06-08 if I recall correctly, I presume all tubes are atleast that old or older. He was the second owner, So I'm unsure if the tubes are all performing as they should. The output tubes have signs of corrosion from storage, maybe this is common, however , new to me.

Please advise if I should sit back and listen or replace?

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One other small thing that I've noticed, when the amps and pre amp are powered on and the volume is all the way down I can still hear faint audio out of the right channel, the left channel is almost mute compared to the right channel. This does not change when the channel levels are adjusted individually, the amount of sound stays consistent regardless of the level adjustments.

When the volume is turned on, everything functions smoothly as it should.

This is a very nit picky observation, I just want to ensure that it's not a precursor to some other issue that could become dangerous or damaging.

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The bleed through on one channel is indicative of the master pot not grounding out completely at stop position. It may get worse with time, but nothing to worry about.

 

Not a bad idea to replace the tubes, and this will take any question mark out of your mind. Could cause the sharpness you hear also. I would put the Ruby KT88's in them from Doug's tubes. The ones that are AKA Penta Labs. http://www.dougstubes.com/power-tubes/ruby-kt88-v-str.html

 

For the Rectifier, you can splurge and put NOS Mullard GZ34's in there or get some new Sovtek 5AR4's from Doug's tubes as well. The Mullard is slightly better sounding IMO, and last much longer, but not much gains in performance really for the cost. You can put new Sovtek 5AR4's in there every year or so very cheap. http://www.dougstubes.com/rectifiers/5ar4-gz34/sovtek-5ar4.html

 

If you want really good front end tubes, go with the Mullard CV4003 in the 12AU7 slot and Mullard standard NOS 12AX7's.

http://www.upscaleaudio.com/12au7-ecc82-cv4003-5814-6189/mullard-cv4003-12au7-vintage-new-old-stock/

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj2kLPn9pvMAhUJ5yYKHW4BBpMQFghXMAA&url=http%3A%2F%2Fwww.audiotubes.com%2F12ax7.htm&usg=AFQjCNEQOc-wWqSO_1Xcx0QAGNcEetvshw&sig2=VFmgZVLyw8M-FElAVe2usQ

 

On the Brent Jessie site, scroll down till you see the Mullard Matched Pair from the 60's, for $185 per matched pair.

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Attributing sonic characteristics to a rectifier tube is a common myth.  It does not have a "sound," and will not affect the sound of the equipment, as long as it can provide the voltage and current needed to maintain the operating parameters of the tubes in the signal path.  Longevity, as was mentioned above, may be another issue entirely and depends on the design of the power supply.  As to replacement intervals, like any other tube, it cannot be based on a given amount of time, but rather on the number of hours of use.  Obviously, someone who uses the equipment for only a couple of hundred hours/year, for example, will not need to consider replacement after that length of time.  Small signal tubes can literally last forever, while output tubes will have varying life spans depending on the circuit design.  In the case of the latter, in a properly designed amplifier, it's not unusual to achieve a life span of even 25,000 or more hours.  If you see numbers suggesting that replacement is needed after only 1000-3000 hours, I'd look for a different piece of equipment.

Maynard

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Oh, and your preamp tubes will have the most influence, followed by the amp driver (12AX7). The phase splitter makes the least influence, but IMO should be a tough @$$ tube.

 

I have had a Peach (brother of the Blueberry) for around 10 years and use it regularly to this day.  Still love the sound.  I also have VRDs.

 

I will echo this post that the small signal tubes in each unit matter most.  You can have fine sound with today's current production tubes, but the NOS tubes can be a real improvement if you get into the "hunt".  It really is a hunt to find the best NOS tubes (actual new ones) and not get ripped off while spending all your money.  Enjoy.  Those are some nice pieces.

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What have your experiences been with UpscaleAudio?

Kevin is a great guy and an absolute tube fanatic. His recommendations have always been spot-on. His pricing is simply a reflection of his expertise, well worth the extra few dollars to insure you are getting what you paid for. :)

 

TS Matt.

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Yep. Upscale is great. I have had a couple issues with output tubes, and they don't question it at all, and just sent more out.

I have had better luck with Doug's though for output tubes in the context of reliability. That, and they have the output tubes I like.

Edited by paul79
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SNIP: "For the Rectifier, you can splurge and put NOS Mullard GZ34's in there or get some new Sovtek 5AR4's from Doug's tubes as well. The Mullard is slightly better sounding IMO, and last much longer, but not much gains in performance really for the cost. You can put new Sovtek 5AR4's in there every year or so very cheap. http://www.dougstube...ovtek-5ar4.html"

 

Another alternative is to find and acquire one or more of the mislabled Sylvania Fat Boys in place of the Mullard GZ34 rectifier.

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