Hagerman Trumpet MC (12AX7 Tube Suggestions)


I have recently acquired a Hagerman Trunpet MC and I am extremely pleased with it.

Desire to assemble some 12AX7 sets of (Almost) NOS Tubes to Tube Roll. 12AU7 positions are purchased but the 12AX7 Tubes are a minefield and somewhat costly after my research.

First question; Have any Owners here used the 5751 Tube in the 12AX7 positions?

Second question; Have any Owners here had any sonic success with 12AX7 USA Brands such as Sylvania as an example. I am reading mixed longevity views on the RCA Blackplates and not many good comments on the GE types.

I am very gunshy on the Re-Issue 12AX7 Tubes also.

I primarily listen to Classic Rock, Progressive Rock, Folk, and some Classical.

Suggestions would be much appreciated.

 

djohn

@mulveling

Teles are expensive from “trusted” sources but they’re really quite common. So many of these were imported to USA, e.g. in Fisher gear. No need to overpay for Teles. Find a few “used tests strong” pairs and keep the best. Of course this works much better if you or a friend have a tube tester.

Agreed. I have had good results from rebranded Teles (and Mullards). If you know what to look for, you can get good deals vs factory labeled tubes. Being willing to try some some from other than "trusted" sellers with good track records can also bring your cost down significantly. I think I got all my vernerable old tubes in my Trumpet for about $400~450ish total. For 6 great old tubes, that is actually a pretty good deal.

For my ears, well worth the extra cost in the Trumpet, and my mix transformed the sound significantly in a good way, to me. Heightened detail with smoothness, warmth, and good weight. But, we all have different subjective tastes.

Tube rolling is a subjective sport.

You guys all do realize that a 5751 affords less gain than a 12AX7.

@mulveling I also reviewed your previous Posts on the Trumpet extensively before purchase. I was especially struck that you compared it with the Herron VTPH-2A which I also own so I wish to Thank You also.

You made me look at the modern Tung-Sols and this warning was on the Viva Tubes Site; " These tubes are great for linestage preamps, but generally not phono stages where a very low noise floor is required ".

It looks like with your comments and bkeske's comments that I have to search and pony up for the Telefunkens.

@djohn

Awesome! So glad you’re enjoying it :)

Just this past week I’ve been playing the Trumpet MC with Plantinum grade gold pin Tung-Sol (Russia) 12AX7 from Upscale Audio - no noise problems there. Maybe Viva just doesn’t like selecting them for this role ;)

But certainly, a good set of Teles will be amazing. I need to dig them up again from my stash. I ’ve been playing with lot of gear the past few years; now trying to settle things down a bit - the ARC Ref 3SE is sold to a friend, the VAC Renaissance SE reigns again in the now all-VAC main rig with Tannoy Canterbury GR, and the new fun 2nd system at my girlfriend’s home is anchored by a really nice set of Tannoy Glenair 10 and this Trumpet MC.

I just went through my photos and see that a couple years ago, when I was really enjoying the Trumpet MC in the main rig (it holds up extremely well and is still probably the best I’ve heard my Benz LPS), I had it stocked with a quad of Tele ribbed plates. So it can use the extra detail and dynamics of this variant (versus smooth plates) without getting too bright - but I also had those warm Mullard CV4003 (12AU7) to balance them out a bit. Shame that Upscale finally ran out of those :(

As @lewm points out, 5751 has a lower mu than 12AX7 - 70 versus 100. But most tube circuits are quite flexible for this. By math 20 * log (0.7) - this is a 3dB difference. However, this assumes an infinite load and in practice it is usually less than this (~ 2dB?). Subjectively, 5751 have a different "kind" of sound. I find them to have tighter, sharper, smaller imaging. They sound very clean and precise. Whereas 12AX7 have a bigger, bolder, more dynamic sound - but with a potentially more "grungy" cast to the sound. But again, haven’t tried 5751 here yet. The GE TM BP are a good go-to for a classic 5751 sound. The "holy grail" 5751 are supposedly Raytheon windmill getters or Sylvania triple mica black plates (TM BP) and I haven’t been lucky enough to snag either. The later 1960’s Sylvania gray plates are awfully bright and lean. Sadly that has been my experience with later make Sylvanias across types - you really want to stick to the 1950s and earlier.

One more note on the 5751 tubes tangent - the absolute sweetest sounding of the GE 5751 TM BP are a specific variant only produced between 1953 and 1954. This variant has unusual silver colored metal "clips" crimped over the plate "ears" that normally poke through the top & bottom mica spacers. These "ears" are normally left bare (not just 5751 - all tube types). For some reason GE saw fit to clamp them down extra tight in this case. And for whatever reasons, this version sounds sweetest :)