Proud owner of a new to me VTBP-201s preamp. This thing beat my Warwick Hellborg preamp... it sounds amazing!
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Demeter Club
- Thread starter bucephylus
- Start date
Alright, gentlemen. Without goin into too much of my history wit Demeter preamps, in 30 years or so I have owned 5. All VTBP 201s. All from varying years. My first was an Innovative Audio Systems 201-s that I never shoulda got rid of. The others all a bit different. Some with green circuit boards, some with grey. I have currently what is reputed to be #4. All of them were great, but some were different. The original IAS version was THE best. By far. The most balanced, the most aggressive, the tightest and fastest, and most transparent. The one I have now is the 2nd best. Far thicker, slower, but not in a bad way. Just different. This all could be the tubes used, as it seems these amps are sensitive to tube changes. And tho I've read all the tech specs and advertising from James Demeter over the years, reading folks' personal experiences is a bit different, and more educational. So I'm left with a few questions.
All my units had two 12ax7a tubes installed in both sockets. I never knew until recently that an at7 was used from factory. Not a lot of absolute technical data from the company, plus all mine were bought used, so I simply played them. I read a lot here, found this and a few other threads, and got curious what would happen if I put an at7 in my pre. So I'm gonna. But which slot is V2? Left or right? I haven't opened this unit. I'm not sure if they're labeled. I never looked. So thot I'd ask. I assume it's the one on the right, as if I'm reading left to right, but wanna make sure.
Second question regarding grey vs green boards. Is this truth, or, just another crazy myth? Just before I bought my current 201, I had another, newer, version. I always open up new gear, to clean and check out interiors. I worked in electronics repair a long time. It's just habit. Anyway, I seem to remember it having green circuitboards. But it's been awhile, and I could just think that's what I saw, having read about it somewhere. I sold that pre to a friend who loved it so much he had to have it. I have too much gear, so I sold it. Made him happy. But I regretted it immediately. On a for sale page the next day, I saw another. Guy said it was #4, gave a story. But who knows, right? Thing is, this one does have grey boards, or, more precisely, aged white. What is the history of the boards used? Is anyone familiar? Seems I read, when they started goin to the green boards, James moved manufacturing facilities. In doing so, he found a few "old" boards in the move, and made a limited series of preamps in the old style. The story goes the first two went to Lee Sklar. One powered with a new 800w Minnie amp, the other just a preamp. The 3rd went to Neal Steubenhaus. So my question. Am I remembering correctly, or am I crazy?
All this is just an old gear head's curiosity. It doesn't matter. Well, which slot V2 is matters, but I don't care bout the goofy stories. All I know is that I've finally got smart. And this preamp is goin nowhere. I wanna get the tubes changed correctly. And see if some of the transparency and quickness return from my oldest pre. But even if nothing changes tonally, what I have now is wonderful. I ise mine bout 200 dates a year. And it works in every room, every style, every situation. You can't sound bad with this gear. For sure. Thanks fer the time, gents. And for any info you could impart.
All my units had two 12ax7a tubes installed in both sockets. I never knew until recently that an at7 was used from factory. Not a lot of absolute technical data from the company, plus all mine were bought used, so I simply played them. I read a lot here, found this and a few other threads, and got curious what would happen if I put an at7 in my pre. So I'm gonna. But which slot is V2? Left or right? I haven't opened this unit. I'm not sure if they're labeled. I never looked. So thot I'd ask. I assume it's the one on the right, as if I'm reading left to right, but wanna make sure.
Second question regarding grey vs green boards. Is this truth, or, just another crazy myth? Just before I bought my current 201, I had another, newer, version. I always open up new gear, to clean and check out interiors. I worked in electronics repair a long time. It's just habit. Anyway, I seem to remember it having green circuitboards. But it's been awhile, and I could just think that's what I saw, having read about it somewhere. I sold that pre to a friend who loved it so much he had to have it. I have too much gear, so I sold it. Made him happy. But I regretted it immediately. On a for sale page the next day, I saw another. Guy said it was #4, gave a story. But who knows, right? Thing is, this one does have grey boards, or, more precisely, aged white. What is the history of the boards used? Is anyone familiar? Seems I read, when they started goin to the green boards, James moved manufacturing facilities. In doing so, he found a few "old" boards in the move, and made a limited series of preamps in the old style. The story goes the first two went to Lee Sklar. One powered with a new 800w Minnie amp, the other just a preamp. The 3rd went to Neal Steubenhaus. So my question. Am I remembering correctly, or am I crazy?
All this is just an old gear head's curiosity. It doesn't matter. Well, which slot V2 is matters, but I don't care bout the goofy stories. All I know is that I've finally got smart. And this preamp is goin nowhere. I wanna get the tubes changed correctly. And see if some of the transparency and quickness return from my oldest pre. But even if nothing changes tonally, what I have now is wonderful. I ise mine bout 200 dates a year. And it works in every room, every style, every situation. You can't sound bad with this gear. For sure. Thanks fer the time, gents. And for any info you could impart.
James Demeter posted this in one of the threads referring to the VTBP-M-800D, the 201 with the Minnie amp (I've happily got one). And yes V2 is on the right as you face the front of the amp:
"I designed the unit so they V1 did all the amplifying and V2 did the current driving to the effects loop and most importantly, supplied the current needed to run the Jensen transformer which provides the differential output which drives the power amplifier. Using a 12AX7 in the V2 position will hurt the amplifiers overall performance and in general not sound good. Because V1 does all the voltage amplifying changing it will give the greatest sonic impact. In general large plate 12AX7's sound warmer (12AX7LPS or Tung Sol)) and smaller ones quicker (12AX7EH or JJ). V1 is the tube if you are Facing front on the left or closest to the input Jax. Thanks to all the Demeter owners for there support, James"
Also quick question for 201s owners... does your guys’ preamps have a slight tube hum at idle?
I've owned a few, and only in a very quiet room have 1 or 2 of mine had that "issue". Which really isn't, since the hum is so low. There is an output trim control inside the unit. If I'm not mistaken, it is designed to match its output signal to the input requirement of different power amps. It could be your output trim is set high, thus accentuating the hum. My particular power amp is known for needing more signal than some others to achieve its full output power. The internal trim of my Demeter is at unity, and has no issue driving my power amp to full. By contrast, I also use an SWR Interstellar Overdrive preamp. It's output isn't as strong as the Demeter, I have to push it quite a bit more to achieve equal volume. I say that because maybe your amp or recording device is very sensitive, and maybe reducing the interior output trim on the Demeter might fix your hum issue. It could also easily be an aging tube. I have had tubes cause hum in these preamps. That's a semi easy check, if your preamp has two 12ax7a tubes in it. With the power off, switch the tubes. If the hum changes, it's quite possible a new tube will fix the hum.
Overall, the Demeter preamps I've had are really quiet. But house power can be noisy. If I plug my preamp in and hear noise, I'm usually blaming bad power in the studio or hall or house. And, tubes and transformers are "analog" technology. They are sensitive to interference and other type noise from electronics, such as being too close to a tv or pickups. You could try changing its location in a room. Or, flippin switches in the house to cut certain lights. One house I lived in, the coffee maker in the kitchen being turned on would add hum to my bass amps, Demeter included.
Sorry fer the long winded response. But I've fought crazy little noises in my rigs for years. Those are some of my experiences. Hum drives me kinda crazy. But Demeter gear is known for being very quiet. A teeny bit of tube hum might be normal for a lot of reasons. But an extraordinary amount could be lots of things. And with Demeter's very quiet rep, I would suspect lots of things that might not be the preamp at all.
Well, as you can see... My preamp is costructed a bit different than yours. Vertical board for the tube sockets. Different jacks, but does have the Jensen transformer. Different altogether, really. Very interesting. But I still suspect my V2 is on the right. And am gonna change the tubes accordingly.
Mine looks exactly like yours internally and I also replaced the 12ax7 with a 12at7 recently: v2 is indeed on the right.
Right on. That all makes sense. I actually have brand spanking new tubes in there so it’s not the tubes. Could be I’m just not used to a tube preamp noise. The internal trim is at 12 o clock. As for the picture of the inside of the VTBP-201s @bassbooty posted, that’s my preamp actually. We’re good friends. Yours looks like it might be older?
Yessir, Mr Stewart13. It is my belief that mine is an older design. How much older is unknown. The unit I had just previously was a newer one like yours. That was the only one like yours I'd owned, tho. Lotta differences. Improvements, probably. And more quickly made. Quick doesn't mean "lesser", of course. All the ones I've owned were great. And a buddy has the H series integrated 800 watt amp, with the para eq and all. It is spectacular!
But I like these older, VTBPs the best. Not sure why. Part transparency and speed, part just the simplicity of them. I did notice there was a 12AX7A in the V2 of Bassbooty's pic. Mine have always been like that as well. And folk says it hurt performance, but I didn't detect it. These things sound great no matter.
The guy I sold my other, newer unit to is a great friend. I'll ask him about hum at idle on that one. He an I sub gigs for each other regularly. Maybe we can meet up and compare. I've never had two in a room simultaneously to do comparisons. Might be fun.
And I know bassbooty a bit from this site and our mutual fondness fer Warwicks. Cool guy, and wise. Nice ta meet another friend of his.
But I like these older, VTBPs the best. Not sure why. Part transparency and speed, part just the simplicity of them. I did notice there was a 12AX7A in the V2 of Bassbooty's pic. Mine have always been like that as well. And folk says it hurt performance, but I didn't detect it. These things sound great no matter.
The guy I sold my other, newer unit to is a great friend. I'll ask him about hum at idle on that one. He an I sub gigs for each other regularly. Maybe we can meet up and compare. I've never had two in a room simultaneously to do comparisons. Might be fun.
And I know bassbooty a bit from this site and our mutual fondness fer Warwicks. Cool guy, and wise. Nice ta meet another friend of his.
On the topic of tubes and Demeter amps...
@ahc ’s quote from JD is the reference point.
From there, my preference for V1 in the dual tube pres is an older Sylvania Gold Brand 5751; but, the one without the gold pins. The 5751 has to my ear a superior depth, for which I gladly trade the little bit of output amplitude difference.
The choice of V2 seems to be pretty irrelevant, as long as it’s a 12AT7 class tube. I discussed this with James, and he concurred.
The single tube preamps, like the Bass400 are a whole different animal. In that design the higher output 12AX7 is practically a requirement. And for that preamp, my preference is the Amperex Bugle Boy.
My fav preamps by a long shot. Just TONE.
@ahc ’s quote from JD is the reference point.
From there, my preference for V1 in the dual tube pres is an older Sylvania Gold Brand 5751; but, the one without the gold pins. The 5751 has to my ear a superior depth, for which I gladly trade the little bit of output amplitude difference.
The choice of V2 seems to be pretty irrelevant, as long as it’s a 12AT7 class tube. I discussed this with James, and he concurred.
The single tube preamps, like the Bass400 are a whole different animal. In that design the higher output 12AX7 is practically a requirement. And for that preamp, my preference is the Amperex Bugle Boy.
My fav preamps by a long shot. Just TONE.
I would say VERY slight. But, A) none of that goes out of the Jensen, and B) once the thunder starts, that little bit of hum tends to disappear.
Thanks! I actually had that second 12AX7LPS in there because I was still waiting for my 12AT7EH in the mail. I’m a Warwick guy as well! Sounds amazing through this preamp.
Man, in the years I've been playing, and my earliest Demeter/Innovative Audio Systems was my first real great piece of gear, I've played a hundred or more basses thru a Demeter preamp. Everything sounds good thru a Demeter. Coincidentally, the first store I worked in where, after reading Bass Player Magazine's preamp shootout issue, I realized my store had a used Demeter that no one recognized. It sat forever, cheap. Soon as that issue hit, I went and asked my boss for it. That was my first. Anyway, that store was also a Warwick dealer. And I got to play all kinds of golden era Wicks, from the earliest bolt versions to original Nobby Meidels and NT Stage Ones and Thumbs. It was the Wenge that got me. Folk say wood doesn't matter. But in the case of Wenge, it certainly did.
I don't own a Warwick today. Dumb, really. But I'm a minimalist. Two basses. Only. My last two Warwicks were unreal. But the gigs I do and the way I play aren't suited to boutiques. I feel guilty dinging them up. Ha! Goofy, but truth. One day, I'll get another, less high end Warwick. But today I've got a couple Leo Fender designed basses that are less valuable. I don't mind beating them up. Ha!
What changes did you experience with new tubes? The AT vs AX? And were they subtle or blatant? I've changed my tubes, and tho I believe I hear subtle differences, especially the noise floor, my unit is DEAD quiet, there's nothing overtly different in my tone. The pre feels more "lush", and the eq seems to work more apparently, meaning, less pot rotation affects the tone more, but there isn't a huge difference in the great tone I had before the change. It may show up in the D.I. at my next show. Or, at stage volumes which I can't attain at home. But just wondering what you experienced, for a reference of what I might listen for.
I don't own a Warwick today. Dumb, really. But I'm a minimalist. Two basses. Only. My last two Warwicks were unreal. But the gigs I do and the way I play aren't suited to boutiques. I feel guilty dinging them up. Ha! Goofy, but truth. One day, I'll get another, less high end Warwick. But today I've got a couple Leo Fender designed basses that are less valuable. I don't mind beating them up. Ha!
What changes did you experience with new tubes? The AT vs AX? And were they subtle or blatant? I've changed my tubes, and tho I believe I hear subtle differences, especially the noise floor, my unit is DEAD quiet, there's nothing overtly different in my tone. The pre feels more "lush", and the eq seems to work more apparently, meaning, less pot rotation affects the tone more, but there isn't a huge difference in the great tone I had before the change. It may show up in the D.I. at my next show. Or, at stage volumes which I can't attain at home. But just wondering what you experienced, for a reference of what I might listen for.
FYI Demeter Club peeps: I just learned in this email reply from Demeter that a straight VTBP-201s preamp without a built in power section is designed to be used with two 12AX7 preamp tubes in it:
Last edited:
