Phil X's amp

[capgreed]

More angles perhaps ? ( lousy pics i know ! Not mine )

http://www.partage-facile.com/KOH5VPW8U ... t.zip.html

[Markusv]

Hi Plexi

Thanks!
Comment on their sound please if you can??
Thanks in advance

Markus V

[67plexi]

The vibrato sounds good way better than a fender
As far as the amp goes not to impressed.
Intensity has a 6AV6 7pin 1/2 of a 12AX7
Speed 12AU7

[hitchcaster]

played one like that,... it did do a cool thing with buckers and p90s.... I remember thinking it was dark and sort of hard to play, but had some cool crunch tones. not Grail so I didn't buy one... not for everyone id guess. gut shot looks worse then it sounds.... doesn't look like it would survive long in the band trailer either

[shoggoth]

I am respectfully begging anyone to explain what they know please. Meaning how do they function in the circuit etc?

This site explains how the Magnatone vibrato works: http://www.geofex.com/article_folders/p ... phase.html

[FUCHSAUDIO]

Just serviced one. EIther the Vibrato wasnt up to snuff or I'm missing something. The tremolo sounds like tremolo, not terribly special. BTW: The cathode resistor for the power tubes needs to be 330 ohms. The 150 uses the 6v6's at over 30 ma each and bakes them pretty hard !! Not an impressive amp in build or tone imho.

[Markusv]

Thanks to all
My question relates more to the type of varistor used. In the pic above they are not the tubular jobbies I have seen previously. Apparently the circuit's sound is very dependent on type of varistor

M

[FUCHSAUDIO]

Apparently the type and the matching is critical. I had a long chat with Obeid Khan at NAMM about the new Magatones (which are build lovely btw and sound excellent). They spent a great deal of time sourcing our the varistors and matching as well as finding the proper window of tolerance for the circuit.

[Markusv]

Yes apparently if you use anything but copper oxide varistors (discontinued) the results are disappointing
Some folks have tried other solutions with varying success
This is a project I have been eyeing for 2 yrs now and am not getting to
Thanks for the input everyone

[Smokebreak]

Markusv, I built one of these a few months ago. here is my thread : https://tubeamparchive.com/viewtopic.ph ... hlight=214
I based it on the Titano schematic, and more specifically, on ev0u812's revised schematic, which cascades the two inputs. If you search this forum for "213" "214" etc. you will find a lot of good info.
You should join the mag/valco yahoo group if you haven't. There's a lot of good info there too.
The amp sounds gorgeous to me. I tried some current production Littlefuse MOV at first, similar to the ones mentioned earlier in this thread, as they produced tremolo, not vibrato...though a very nice tremolo indeed. I had heard that the EvilX was using the NOS, so I'm kinda surprised to hear they are using new production, as Fuchs has attested to.
I finally just bout the Workman NOS varistors and they indeed produce the classic Maggie pitch-shifting vibrato. There are some clips in my thread. Vibrato aside, the amp has thick, warm cleans, and turns into a rock machine when cranked. I ended up installing Merlin's 1M at the concertina grid "trick" that eliminated some buzzyfizzies when cranked, and put a 1:1 voltage divider at the cascade.

The subject of suitable current prod varistor replacements has come up a lot, and for a while Martin Manning and I were mailing back and forth, as he was designing replacements and I was testing them in this circuit. There is some info on that in this thread : https://tubeamparchive.com/viewtopic.ph ... =varistors

I've also got some NOS Russian MOVs that are reported to work, but I've been sidetracked with other projects. I'll get those in soon and report.

All in all, it was a very challenging and rewarding build for me.

Oh, of course Magnatone is back in business, and using some new prod varistors that produce real vibrato. I've been out of the varistor loop for a couple months, but at the time everyone was trying to source those, and getting close...