Tube choice for Dumble amps NOS Vs's New Production?

[Mark]

I was wondering if any of you can shed some light on the valves used in Dumble amps.

I recently put some Sylvania 5881's in a D'Lite and the amp sounded a bit darker and smoother than the Winged C's and Tungsol reissue tubes that had been used previously.

I also curious about the pre-amp tubes too.

Looking forward to hear of your experiences.

[talbany]

I was wondering if any of you can shed some light on the valves used in Dumble amps.

I recently put some Sylvania 5881's in a D'Lite and the amp sounded a bit darker and smoother than the Winged C's and Tungsol reissue tubes that had been used previously.

I also curious about the pre-amp tubes too.

Looking forward to hear of your experiences.

Mark
As many here will state preamp tube choices in this amp can and will greatly effect the amps tone.. Therefore becoming a somewhat subjective topic for discussion here, so trying to recommend a certian tube or set's of tubes that you may like or dislike is rather difficult in an open forum..
There are many variables involved here like gain factor and trans conductance of a particular tube and the fact that preamp tubes (in this case are cathode biased) are also dependant on that particular tubes current draw which in turn effects the bias points just like a power tube..
Example:..A given tube that sounds good to you in one amp might not sound and perform the same in another amp

Also being that a D-Style amps OD sides topology is not discreet (clean channel feeds the OD) V1 and V2 work together to generate the OD tone so it becomes Dependant on how the 2 interact..
Most here including myself prefer the NOS over current production tubes mostly for their smoother more Dumbley type flavor (in most cases) associated however due to the above statement not all NOS tubes are a guaranteed to deliver for you good results..
Newer type tubes to me do have a certian character to them just like your Sylvania's and winged C's (brighter darker etc.) which helps when choosing certain brands you might prefer or types like perhaps a long plate etc..Still even then you will get fluctuations in tone and breakup character tube to tube..
For NOS most here like Amphrex,Mazda's,RCA's and in some cases Mullards, to name a few..
New Productions are the JJ's, EH's seem to be favored here..
For me I prefer long plates LPX or ECC-803's in the PI..(adjust balance)
Keep in mind tube testers will help to narrow the field by insuring a healthy in spec tube with good gain/transconductance and matching as this insures the tube is performing as the circuit was designed..
Others can chime in on what they like..

Hope this helps..

Tony

[212Mavguy]

+1000 for Tony's post.

Kinda scary being a newbie and daring to follow one of the great ones...

To my ear's experience certain tube maker's products within a given tube type have their basic sonic signature, with some variances within. Also, certain tube makers also have a familial sound between slightly different tube types.

For instance, in Raytheon, to my ears there is a "Ray family" tone that has strong similarities from the 12ax7 long blackplate rectangular halo to the 5751 blackplate windmill getter, to the red print triple mica black plate 12at7.

Within the "Philips" family for shortplate 12ax7's from Mullard, Amperex, Miniwatt, Philips/Blackburn, Philips/Heerlen, Valvo, Electrohome, Rogers, Siemens and even Matsushita with 45 degree getter flashing strong "family" tonal characteristics are common to all of these closely similar in build 12ax7's. Each brand does have it's own version of the family's tone.

Before choosing various vintage tubes from my collection for voicing my new C-tone 50w HRM I started a similar thread in the Ceriatone forum in the Dumble section. Quite a few responded, and their responses caused me to remember certain tubes in my collection for their sonic characteristics.

My ears tell me that no one preamp tube sounds best in all amps, rather that tubes respond differently within different amps, even of the same amp model. What works for me in voicing amps for myself as well as other players is finding the tubes that express both the amp's basic voice as well as the player's wishes for their personal tones.

Then, I thought about what kinds of tones I was hearing in the youtube clips, and came up with the impression that (yes, I know this is controversial) Classic dumble OD tones are not super high in gain, smooth, warm, fat, harmonically rich, sustain-y with a slightly rolled off top end combined with harmonic bloom during the sustain of long notes. I was floored by the tones of a Gibby "Lucille" guitar doing a pickup test through a d-style amp in one of my first listens.

A couple of posts in that thread reminded me of some tubes in my collection of 500+ vintage tubes that I tend to not like in guitar amps... namely, the Telefunken smooth plate and the one I prefer between the two, the ribbed plate 12ax7.

But thinking about the smooth plates' big bottom, full mids, and slightly rolled off top end as well as their control over harmonics and unusually compressed and sustainful dirty tones, I thought that they might work well in my HRM. So I found a very strong and tightly matched sections smooth plate and put that in to the PI, a strong and matched within 10% Philips 7025a/12ax7a Blackburn build in V2, and another 'funken very strong, balanced within 10% smooth plate in V1. From my reading I have been given the impression that a fair amount of early Dumble amps have Sylvania 6l6gc's in them. So I sourced a lightly used pair from fleabay and as luck would have it, they biased to less than a half millivolt difference between the two at 35mv. Down the road I might experiment with some Siemens el34's and some Emitron and Genalex kt66's from my collection. But frankly I'm more than happy now, I actually drooled onto one of my Heritage guitars while playing through this rig a couple weeks ago.

The classic, Dumble-y tones came through for me big time, playing through a custom modded old Peavey 2/12 semi closed back cab done up a la THD Longhorn style. A slot crosses the back, loaded with rather rare JBL g125's in series for 16 ohms. Cranking up the OD trim and increasing the gain gave up some rather Marshall-y snarl, even using 6l6's instead of el34's. But the earliest JTM45's did use 5881's, a member of the 6l6 family.

I also ordered a C-lator and stuck in it a very strong 'funken ribbed plate 12ax7 for the slightly brighter top end compared to it's smooth plate cousin and also for it's sustain-y compression. The combination of all the chosen tubes, C-lator, amp design, and cab combined to provide some very nice, sweet, violin-y sustain on the OD tones, with fat, full, harmonically rich cleans.

I don't have the equipment to post clips, and my chops are not up to the kind of snuff I know that this forum's members often have. Sorry. What worked for me might not work for you, but I thought about the tubes' sonic characteristics before plugging them into the sockets, and that is why things worked out so well for me IMHO. YMMV with your setup.

[67plexi]

Mark, I have no idea what voltages you are running in your D’Lite.
I will follow the leader as a starting point. Amperex/GE/RCA/Sylvania 7025 17mm long plate.
Sylvania 6L6-GC STR-415 or 6L6-GC STR-387.
I have no clue on new production valves/tubes.

Regards, Steve.