Anyone like EF86 as a preamp tube ?

[loudthud]

A Dallas guitar shop that gives me amps to repair from time to time has a Matchless DC30. The sales guy there says it's one of the best amps he's ever played. He likes channel 2, the EF86 channel. I'll get a chance to play it next week (if it doesn't sell).

Reverb listing: https://reverb.com/item/60663167-199...cabinets-green

Schematic: https://el34world.com/charts/Schemat...s_dc30_old.pdf

Any opinions on the EF86 as a preamp tube ? Any good source of new tubes other than NOS ? Anyone tried a 6AU6 ? I have some NOS.

[Mick Bailey]

I regularly serviced a Matchless HC30 (the head version of the DC30) and really like the EF86 channel. Also over the years I've serviced and repaired quite a few amps with EF86 preamps and one of my favourite combinations is the Bird Golden Eagle 15W amp which has an EF86 preamp and EL84 output tubes. I owned an old Vox AC10 for many years with the same magical combination. Until recently I had a good stock of NOS Mullard tubes, but when these dried up I struggled to find any modern tube that was not excessively microphonic right out of the box. Maybe 1 in 5 was just about OK, but nothing special. It's frustrating opening box after box of new tubes and rejecting them. I think tube quality is the biggest problem with the EF86 as a preamp.

[Leo_Gnardo]

I think tube quality is the biggest problem with the EF86 as a preamp.

Definitely! I was lucky to score half a dozen with GE paint on them but underneath it they were Mullards. Every one a peach! Occasionally I have an amp come in with ElectroHarmonix EF86 that's rattling, howling, and making noises like a steam radiator about to explode. Not impressed - except with the amount of racket one of these can make. I'll be none to happy when I run out of my GE/Mullard stock on these, only 2 left.

As far as what they "sound like" seem to be obviously compressed but that can be a good thing. Notably different from the usual 12AX7. Some folks I'm sure wouldn't notice one way or the other. @ 25 years ago got to fix an AC15, I think it was Jimmy Weider's, sounded so impressive I added AC15 to my short list of favorite amps.

[Mick Bailey]

I had a large stock of NOS Mullard and Brimar audio tubes and for many years just charged them out at what a new Sovtek or whatever was going for at the time (£7/$10 each) . I never even considered that old tubes were worth anything special - I just got on with repairs and fitted them until they ran out. It still smarts that I let so many go - full retubes of AC30s and the like. Those owners got a really good deal. I bought them originally at a time when there was none of this ridiculous markup on NOS. Boxed Mullard ECC83 and EF86 cost me £1 each ($1.14 at today's rate). I still have some NOS boxed Telefunken, Mullard and Brimar tubes, but I'm now keeping these for my own amps.

[The Dude]

Agree with the others. It's getting harder to find good EF86 tubes that aren't microphonic. Last time I worked on a DC30, I bought a lot of 10 NOS from Ebay. I just kept plugging tubes in until I found a non-microphonic one. I still have some left, but have no idea of their quality, until I need another. I saved all of them because I've found a tube that's microphonic in one amp may not be in another. The same goes for gain stages. All that said, I do love the sound of those amps. One of my favorite semi-clean tone guitar players (Todd Nichols of Toad the Wet Sprocket) plays a DC30 and I love the tones he gets.

[loudthud]

I played the amp Tuesday. It does sound good, but I don't know if it's the best amp I ever played. I'll try to play it again, but I may just have to build one.

I looked up prices for EF86 on AES.

JJ $42.05
EH $32.10
Tube Doc $33.95
"Vacuum Tube" $49.95

Ouch !

Then there's the transformers. That looks like about $300.

The four EL84 thing got me thinking about the TrainWreck Liverpool. Different preamp and it uses feedback in the power amp.

[Mick Bailey]

Another EF86 amp that's on my list of things to build is the Dr Z route 66. Maybe with a post-PI master volume. I've never heard one in real life, but its a simple and relatively inexpensive amp to build. It would be even better with reverb, but that would take a way from the simplicity.

[blind Blake]

Yes I love the sound of that valve - I have it in V1 of my EL84 amp. Sounds beautiufl