Nos ribbed telefunkens- for her pleasure!
Tube Rolling for Pre-amps?
I have an Audio Research LS-16 that feeds a Madrigal Proceed HPA2 solid state amp.
I did not choose this equipment; it was given to me. From what I can tell the original owner spent a good bit of time matching up these two components with the speakers, Aerial Acoustics 7Bs.
The tubes in the AR are original. Probably 10-15 years old? But with an extended period of not being used.
The system sounds good to me. I don't need to change anything.
However, I've been told that the tubes are old and may need to be replaced soon. I've also read a little bit about tube rolling but most of the articles I've seen talk mostly about tube rolling with amps and not pre-amps.
So I have some questions:
1) If the original owner wanted a system that sounded like a 'tube' system, why not have a tube amp and pre-amp? Does it make sense to have a tube pre but SS amp?
2) Other than outright failure, how will I know if my tubes _need_ to be replaced?
3) With a SS amp, will changing tubes in the pre-amp have a noticeable impact on SQ? In other words, is tube rolling for a pre-amp played through a SS amp a thing?
4) For someone like myself who is happy with the system and who is also easily frustrated by A/B testing is tube rolling the pre-amp even worthwhile? I can almost always hear a change when comparing various components but only rarely am able to say A is better or worse than B.
( I probably can't even articulate effectively what I look for in terms of SQ except that I like the bass to be tight, precise, well defined and not boomy. I do not like the music to be overly bright or tinny. I like depth and lushness but not overly warm. Not sure if these are things you alter with tubes.)
Thanks for any advice.
I did not choose this equipment; it was given to me. From what I can tell the original owner spent a good bit of time matching up these two components with the speakers, Aerial Acoustics 7Bs.
The tubes in the AR are original. Probably 10-15 years old? But with an extended period of not being used.
The system sounds good to me. I don't need to change anything.
However, I've been told that the tubes are old and may need to be replaced soon. I've also read a little bit about tube rolling but most of the articles I've seen talk mostly about tube rolling with amps and not pre-amps.
So I have some questions:
1) If the original owner wanted a system that sounded like a 'tube' system, why not have a tube amp and pre-amp? Does it make sense to have a tube pre but SS amp?
2) Other than outright failure, how will I know if my tubes _need_ to be replaced?
3) With a SS amp, will changing tubes in the pre-amp have a noticeable impact on SQ? In other words, is tube rolling for a pre-amp played through a SS amp a thing?
4) For someone like myself who is happy with the system and who is also easily frustrated by A/B testing is tube rolling the pre-amp even worthwhile? I can almost always hear a change when comparing various components but only rarely am able to say A is better or worse than B.
( I probably can't even articulate effectively what I look for in terms of SQ except that I like the bass to be tight, precise, well defined and not boomy. I do not like the music to be overly bright or tinny. I like depth and lushness but not overly warm. Not sure if these are things you alter with tubes.)
Thanks for any advice.
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Think the tube pre and SS power covered above (also what i use) pre really defines the sound. and tube rolling in pre doe make a differance most of all in a phono input stage as levels lower. I switched fine JJ ecc83 for telefunken and then a Siemens 5751 tube and the midrange opened up even more. And then the sound was good and I stopped. If you like the system then just enjoy it |
@n80 my preamp also uses 6922 tubes and six of them so I am always on the lookout for a good value. I was turned onto these by someone in the forums here: https://www.upscaleaudio.com/collections/vacuum-tubes/products/matsushita-national-pcc88-7dj8 It's a 7dj8 and from Upscale at $30 each a steal. I would call the sound very linear with excellent frequency extension and transparency. Not overly warm. And don't stress too much about tube rolling its fun and easy and preamp tubes will last you a good long while. |
These were the best tubes I tried in my LS16MKI when I had it. https://www.upscaleaudio.com/collections/vacuum-tubes/products/matsushita-national-pcc88-7dj8?varian... I tried a lot of different tubes with all my ARC gear. These are really, really good and aren't that expensive. I was lucky and started buying tubes over 40 years ago when they weren't in vogue like they are now and were cheap. I have drawers full of tubes. Could probably retire on what they are worth now... |
@elizabeth : It takes an effort to keep the 'inner audiophile' tame. Even some of the stuff I consider to be wacko beckons at times. But I also have an inner Scotsman that delights in high bang-for-buck ratios which becomes a hobby in itself and helps keep my over-the-top hobby tendencies at bay. I love a bargain that fits a need! @lowrider57 : I don't think I'll end up being a tube geek. Having a back up set makes sense and I'll probably do that if I can do it affordably. But then that's the first step isn't it? Get the back up tubes. Can't resist trying them out. Like the way they sound. Wonder about a different set............. @rodman99999 : Currently my live music consists of the symphony 3 - 4 times a year, opera maybe once a year. But that's not what I tend to listen to on my system. I go to loud rock shows a few times a year. SQ at those shows is never great. Fun shows though. |
Yes- Only changing two tubes(either V1 & 2, or V3 & 4) will generally provide you with a good slice of what can be expected, if all are swapped. I’ve avoided counterfeits and junk, by only purchasing from reputable tube mongers. ie(for nine pin miniatures): Brent Jesse, Tube Depot, or this guy from whom I’ve purchased the most: https://www.ebay.com/sch/audiotubes_de/m.html?_nkw=&_armrs=1&_ipg=&_from= Upscale only refuses to sell their NOS tubes, for use in pro audio equipment. They have lots of NOS 6DJ8 types, for home audio. I found everything that Siemens made, after the early/mid 60s, grey shield CCa, a bit too zingy/bright for my tastes, but- that could just be the rest of my system, ears or preference. I only said what I did, about live music, because after extended listening in good, live venues- one sometimes gets spoiled(perhaps, educated) and the average home audio system MAY then sound, "broken". |
@lowrider57 -Brent Jesse is cool. @n80- call him, don’t try to decipher that website. It will drive you absolutely bonkers. I didn’t deal with him for years because trying to decode his website was like reading a bad spreadsheet. He’s a really good guy, and knows tubes, isn’t overpriced and is very fair in my experience. He’s also not a BS seller, which in vintage tubes is very common. There are also some mistakes that can be made out of pure ignorance. I’ve made them. I bought some NOS Mullards printed on the glass as "Made in Great Britain" or some such. Turns out, back in the day, tube manufacturers shifted production even to unaffiliated companies given demand and supply. My British tubes were actually made by Amperex in the US. The seller (not Brent) didn’t know that, and neither did I. A reliable supplier of tubes is pretty essential, unless you really go full geek. I’m sure there are some posters here who qualify (I don’t mean ’geek’ in a bad way, just that you have to dig deep). It’s another part of the history of this hobby that we live with today and is at times fascinating, frustrating and often maddening. |
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@lowrider57 : " n80, you have no baseline or reference to judge the SQ of your preamp." That's what I'm saying. It is a blessing and a curse! The blessing is that I think it sounds great. The curse is that it might not. ;-) I don't remember where those prices came from. Just a Google search. I don't know anything about types. This is what comes in the pre-amp: 6922/E88CC dual triode. It takes 4. |
I do have the MKI which means 4 tubes to replace or try rather than 2. @rodman99999 : "There’s no problem, trying just one pair per gain stage, at a time, to see if you like the change." I’m not sure what that means. Does that mean I can just change 2 of the 4 tubes to get an adequate test of SQ? "NOS Siemens(tighter bottom, airier and more detailed/cleaner than stock)." That sounds like what I would want. A search reveals that gold pin versions of those tubes go for around $40 - $75 each. Does that sound right? How careful do I need to be to avoid fakes or crappy tubes? " IF you’re actually happy with your sound, why fix something that isn’t broken? Just don’t go listening to a lot of live music." I am actually quite happy with the sound, but there’s always that audiophile neurosis that whispers in my ear that maybe it could be better and I just don’t know how bad it sounds right now. But I don’t understand what you mean about live music. Live music recordings? I only have a few, all on vinyl. Not all that crazy about live recordings, but why would live recordings be a problem? Edit: At Upscale Audio those Siemens tubes are $135 each and their site says they do not sell NOS. Does that mean they are used? How do you know how many hours are on them? Well, its all academic since right now there is no way I'm spending $500+ on a set of tubes. (I realize that's chump change for serious tube rollers). |
You should have a spare set of tubes as I and others have stated. I like the idea of comparing the new pair with yours, then use the tubes that sound best. Even though your preamp may have sat idle for a long period, the former owner may have put a lot of hours on his system. Or he could have left the preamp powered up for long periods of time. |
Right. My point is, tube degradation with small tubes is gradual. You may not hear a nasty and don’t necessarily know that it isn’t performing as fully as it could. Testing only tells you so much. For example, I use NOS ribbed Tele 12ax7s in my Lamm SET amps. (None of these are truly ’never used’ -well, maybe once in a while at a significant surcharge over the already premium price for "pulls"). Six months ago or so, I had a sense that the amps weren’t as sparkly in the high frequencies, and nothing else in the system was amiss. I got another pair. Voila! Back to that sound I love. (The replacement pair was noisy, and the vendor swapped them out for another pair that now works fine). And that 10,000 hour figure cited for some of these high grade tubes? Sure. I’ll accept that. But those "NOS" Telefunkens on the market? How many hours have they already clocked? ( I do actually find never used vintage tubes sometimes, but it’s getting harder, and the popular ones, like the 12ax7 Tele--well, good luck. Not trying to be negative, just my reality). I rolled bags full of 6dj8 equivalents back in the day. Literally- a few full sized shopping bags of them over the years. |
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Tubes don’t get old/weak, from age(only use), unless they have a vacuum leak. If you’re really concerned about the remaining life of your 6922s(assuming yours isn’t the MkII), you might send them to theses guys, for testing: http://tctubes.com/tube-testing-service.aspx I’ve found them accurate, honest and reliable. Regarding your last question, YES- the presentation you’ve described, can be adjusted with the preamp tubes. Any good power amp, will faithfully pass whatever signal it’s fed, so- make it the best you can. ie: NOS Amperex(a little warmer than stock ARC tubes), NOS Mullards(a lot warmer than stock), NOS Siemens(tighter bottom, airier and more detailed/cleaner than stock). There’s no problem, trying just one pair per gain stage, at a time, to see if you like the change. I rolled tubes through a couple different ARC pres, never trying anything but E88CC/7308 (or better) iterations, with gold pins. I settled on the early Sixties, grey shield, Siemens CCa. I’ve six in my CDP, now(glad I bought extras, way back when). Good information, here: http://www.audiotubes.com/6dj8.htm Then again- IF you’re actually happy with your sound, why fix something that isn’t broken? Just don’t go listening to a lot of live music. |
Small tubes often don't fail dramatically in the same way that amp power tubes can- but they will lose their high frequency extension and punch over time. It's almost like a new pair of sneakers- more bounce. I'm not sure it is worth getting carried away with expensive NOS tubes in your preamp- look at the complement- are they 6Dj8? (that was pretty common then), and there are many types and manufacturers. Obviously, you won't know what the tubes sound like til you hear them in your unit and system. I'd refresh them for sure, but am not up on current production tubes. |
I'll add to @djohnson54 comments. I'm an avid tube roller. At one time I was addicted to rolling NOS preamp tubes when I had a SS amp. Depending on the design of the preamp, rolling in a different brand or style of tube can make a significant difference to the overall sonics of a system. Characteristics such as dynamics, transparency, soundstage can all be affected. Many audioholics change tubes to take the edge off the highs, or conversely to add extension and "air." The caveat is that the amp will play a role in how much of a change in sonics you hear. Your SS amp must be revealing enough to hear the changes from the preamp. But you will hear a difference in preamp SQ or sound signature. Preamp tubes do last a long time; thousands of hours if purchased from a reputable dealer. A dying tube can become noisy or microphonic. But IME, you can tell when a tube has reached its life expectancy when your music begins to sound dull. There may be less extension, a flat image, or less colour or drive to the music. I'm a firm believer in having a set of spare tubes on hand. For this reason maybe you should start shopping for a replacement set. |
@n80 As a person with a tube preamp and a SS amp, I'll share my 2 cents.
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