First effects, now tube rolling ... WHAT'S HAPPENING TO ME?

Well you know MB, the first preamp tube does almost ALL of the tone creation. You'll see much less in the other tubes, by the 12AU7 it's just splitting and inverting.

Have fun, I've put all sorts of different tones in my 4PRO by doing that... Just a warning you could lose yur mind playing with that 1 tube.

BOB

No, but you might end up with an SVT in your bed.

You'll have one before long. You're hooked now, and nothing but a tube power section will sassify. Good time to buy used ones.

I really love the jj/tesla I put in my t max. Super fat and warm.

Munjibunga said:

Jeez. Now I bought a couple NOS/NIB Telefunken ECC83's (gray smooth plate, I believe). I was just going to buy one for V1 in my DB750, then I thought, "Hey! I wonder how one might sound in my WT-800!" So XtraLongScale's going to pop them in the mail to me tomorrow.

Anyway, these were not cheap tubes, so I hope all the hype isn't from folks who use Tara Labs cables. What I've read so far indicates that this swap could take some of the fur off the DB750's tone, which might make it the perfect amp for me.

I also have a JJ Tesla 12AX7 lying around. Would it be a good idea to try that in V2? Any recommendations for the ultimate 12AU7? I know, I know, experiment.

Oh yeah, has anyone ever tried a Tele in a WT-800?

Let's see ... where did I leave my white cotton gloves ...

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tube switching in your 750 might make a profound sonic difference, but having tried A BUNCH of tubes in my WT800B, I could hear NO discernable difference whatsoever...

I started to wonder if the tube was even hooked up in the thing...and even though Bill Fitzmaurice is certain I am susceptible to 'the placebo effect' when it comes to audio gear (Why didn't it work this time, and why is it so picky about when it kicks in and when it doesn't? Placebo effect with front-end cables, but none with tubes in an Eden 800b, rack cables, or speaker cables...?).

In my old Trace, tube swapping was fun, and made a HUGE difference in the voicing of the amp, its response, even effected how well the EQ section worked (or else that finicky placebo effect kicked in again, bigtime)...but in the Eden, nothing...nada...I even tried an old tube from 10 years ago that had a trillion miles on it, that I was pretty sure was absolutely spent...zip.

Sorry. But good luck with your 750, that should be fun.

If I only had a back...

Cheers,
Cameron

Bassflute said:

tube switching in your 750 might make a profound sonic difference, but having tried A BUNCH of tubes in my WT800B, I could hear NO discernable difference whatsoever...
Cameron

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i too tried a bunch of NOS 12AX7 tubes (RCA, Telefunken,Mullard, Amperex) in my Wt500-B with no improvement/difference from the original tube so it seems that with Eden's, tube upgrades don't make much, if any difference.

I have tube rolled in my Gb and old eden amp .. tried old telefunkens that were around from an old stereo, and 70's RCA, sylvanias without beig able to notice a change..

There are some hybrid designs that minimize the tonal impact of different tubes. Genz Benz says that's how they design amps. Can't speak for Eden but apparently they do the same. Honestly, I can never tell a difference with any tube in any amp ever

Let me clarify this so that nothing gets taken out of context...

In bass amplifiers, hybrid or all tube, two particular issues affect all designs to some degree. They are microphonics and tube variability.

Microphonics - Since tubes are an electro- mechanical structure, external vibrations like those from a speaker cabinet can cause these structures to vibrate internally and this distrubs the "smooth" electron flow which modulates the audio signal with the vibration signal. The effect ends up being an underired signal superimposed on the desired signal that vaguely resembles a ghost note, or a superimposed note that may be only loosely musically related. Generally the result is unflattering at best. This is made worse by circuits that use high open loop gain and little to no feedback. The higher the open loop gain, the more opportunity the microphonics has to enter the signal path. Some ofthis can be corrected by good mechanical design but for amps that will sit on cabinets and specifically combos, intelligent circuit design is also very beneficial. I can't speak for other manufactures but I am quite aware of these potential problems and their solutions.

Tube Variability - Tubes by their very manufactured nature are quite variable in several important transfer characteristics. This means that the signal out of the tube may contain variations in gain and tone that are due to these different transfer variables. That's just the nature of tubes and the manufacturing processes. As a designer, there are things that we can do that can help to normalize these effects so that the end user gets a product that is at least reasonably consistent from amplifier to amplifier. The same design techniques that help with microphonics can also be used to our advantage to take a wide range of tube curves and condense these effects into a tighter set of net transfer curves. This involves a combination of feedback, plate conditions, bias, topology and impedances. We have choosen to minimize the wide variability as a benefit to those who purchase our products, so that all of the amps sound as close to the same as is practical. Otherwise, some folks would end up with potentially poor sounding products due only to the variability of the tube. IMO, not very cool.

Every manufacturer goes through this basic design process, each one making decisions that they feel is best for their customer, their product and their marketing. I'm just giving a glimpse of the sorts of things that we consider when developing our designs. Hope this helps.

Munjibunga said:

Oh yeah, has anyone ever tried a Tele in a WT-800? ...

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FWIW, it's not a WT-800, but my experience with rolling tubes in my Navigator was that swapping tubes in that preamp made little to no difference, while swapping tubes in my DB750 (or DB659) made a much bigger difference.

Of course, YMMV.

agedhorse said:

Let me clarify this so that nothing gets taken out of context...

Tube Variability:

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Hmmm... I guess tubes don't vary much from one to the other?

Ah, sorry Andy. I guess I quoted you just before you completed that thought.

Not sure if this is germane to the conversation really, but almost all the TBers that bought the Telefunkens I had for sale are DB750 users. Most other hybrid heads aren't that influenced by tube rolling from what I've read here on TB. I can say that Teles make a rather noticeable difference in my VB-2 and Valve King heads as well as my Presonus Studio Channel vocal pre. This sparked my curiosity to read up about and try other NOS and modern 12AX7s here & there in the future but I kept five Teles for myself so there may be no need

Bassflute said:

tube switching in your 750 might make a profound sonic difference, but having tried A BUNCH of tubes in my WT800B, I could hear NO discernable difference whatsoever...

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Pretty much the case in my old Navigator and current WT-800A... As I like things clear, round, warm though ... I might not be puching the front end hard enough to get the tube excited ...

The Navigator did not respond well to being pushed hard in the studio. At least in my hands, using either a good J or a Rumblefish PJ ... The Navigator sounded best when it was running a little cool and with EVERYTHing possible switched off. No Turbo Boost, No comp, No EQ, basically a gain stage... Sounds kinda drastic for a pre with all those knobs but ... it compared well with a Great River pre inthe recording rack. The GR edged it out with a slightly better noise floor... Pretty heady company for a live oriented bass pre to be hanging with !

So Munji - effects pedals ? tube rolling ? maybe you're bored ? Get a table saw, build a fEarful ...

tombowlus said:

Hmmm... I guess tubes don't vary much from one to the other?

Ah, sorry Andy. I guess I quoted you just before you completed that thought.

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Power failure.

FWIW When I use my DB750 I almost always use a Auralex Gramma Pad between the amp an the top of my cab.

Munji . . .

Man - I really WISHED that the fancy NOS Tele tube made a difference in V1 on my DB750 . . . but I really couldn't tell a difference.

I was always bummed with how dark and mid-focused my DB750 was. Although I still have it and use it for certain projects.

Know what solves the issue?

SA200.

I'm one who found that rolling the nice Tele in my V1 made a nice difference. Not huge. The overall tone and performance across the fretboard improved by becoming more clear and even. I also noticed that the bottom end became tighter and more controllable under my fingers if that makes sense, no whoosh after the note. Also the top end is more shimmery. So.. I guess that is a significant amount of change, but most of it is subtle and I thought it was worth the upgrade.

In general I like the tone of the DB750 and paired with the right cab (HS410, AE410, NV215 ime) it is impressive and a solidly built amp. I have not tried the SA200 but would like to without first buying one...