fillmore west ear killer!!!

[pombagira666]

west fillmore amp is brought back to life

Thanks to those who posted about the necessary adjustments to the amp. Instead of power going to the paddle switch which now only works as standby, the polarity switch has been converted to the power switch.

The ohm selector has been been bypassed, and it has been hardwired for 8,4 and 2ohms. Amp tech found the plate loads were all wrong based on the 16ohm, 8 and 4 selector. The amp came to life when a 16 ouput was placed on an 8ohm load, my amp tech concluded the transformer must have been built for 8,4, and 2ohm. It now pushes out over 200 watts, and the four speaker outputs have been made into two for 8 ohm, one 4ohm and one for 2 ohm.

He did say the wiring was in parts badly soldered, and it looked a little homemade.

Having brought it home, I have to say I am blown away by this amp. It's incredibly loud, sorry LOUD, and the range of frequencies it produces given it only has one pre-amp valve is really incredible. Bright, mids, low bass frequencies have such a clarity of tone.

Some of you have said this is a yard sale amp, well if you do come across one please pass on the amp to me, because I would love to acquire some more, especially ones at a yard sale price!!!!

[Tremelo68]

Just picked up one of these for $50 in non-working condition (though the seller says it worked last time he used it 10 years ago...). Will post pictures soon. This thread has been very helpful already!

Amp seems to be in original condition and not bad at that. Dirty from sitting in a garage. All the tubes look to be original. Possible score for 4 GE 6550s! Will tube test them as well with the new Orange VT1000 tube tester

[pombagira666]

That's incredible news. I really thought the days of finding amp bargains had finally passed especially given the encroachment of ebay into our daily lives. I would suggest you follow the mods required to make this amp safe and useable. You will find it to be the one of the best amps ever made.

[Tremelo68]

Here are some pics:












and here is some craziness! Exposed Phase Inverter circuit and caps! Don't reach into this amp without looking! Not to mention the 6550s will get super hot as well.



I am ordering a Carling progressive switch from Antique Electronics and have yet to fire it up. I noticed that the PI tube installed was a 6na8, which is not a 12AT7. That may be the reason it didn't work when he tested it. The 6550s all check out as good tubes in the Orange VT1000 tube tester. Two rated as 9, one was an 8, and one was a 10. I plan on hardwiring the speaker jacks to the OT taps as well, though I'll leave that Tele switch in for looks. The Cap cans look like at least one and maybe both of the 320uF were replaced. They seem to be glued/epoxied onto the chassis. I have plenty of 12AT7 spares to use. So, my next step will be to variac it up slowly as well as use a current limiter. Test the bias. See if I can get some sound out of it. Then look into replacing the caps.

[Tremelo68]

two more pics

[pombagira666]

It looks like it is in good condition. Can you send pics of the amp as it appears from the outside?

[Tremelo68]

There is an earlier post with 7 pics, awaiting approval from moderator. I should have done multiple 2 pic posts...

[Steve Conner]

I just approved it for you. I guess the forum software must block posts from new members with lots of pictures for some reason. Nice amp BTW

[loudthud]

That phase inverter board came out of a Dynaco Mark III. If you look around, you can probably find a different phase inverter that will fit right in that uses one or two dual triodes.

[pombagira666]

Well I am not sure if you saw this article by the guy who fixed my west fillmore. It may help, and I see the paddle switch has already been changed.

West Fillmore

[pdf64]

Thanks, his website is always worth a nose around, eg see this monster of a project, 8 x 807! Champ CBA-225 Tube Amp
Pete

[Tremelo68]

I did see his page and used it. Thanks.

Yes, the switch is on/off/on type and polarity has been changed to a standby previous to me. I purchased an off/standby/on progressive and plan on putting that in at some point. I put in new filter cap cans and a grounded 14ga power cable and turned it up slowly on my variac. Success! Amp is LOUD and clean. Lots of high end. I mean lots! Why does it even have a bright switch! OMG the highs will shred your ears at stage volume if you use the bright switch.

I have contacted West Labs to see if they can help further with mods and get me a schematic for this model. He mentions "blueprinting" to update the amp for cleaner and less noise. Wondering if he shares that info. 6an8 is the PI. must be an earlier version of the Fillmore.

For now, happy with it. For $50 plus $60 in parts, I have a killer amp. The 6550s all read good on my tube tester and they sound amazing. And I haven't even attempted to bias it yet, though since it has the old tubes it probably is biased for them already.