I've A Question Regarding A New-To-Me West Fillmore.

LongHairFreak · #1 11-17-2010, 09:03 PM

Hey Folks

I know I'm breaking unwritten laws here by not posting pics, but please give me a break this time around.I mean, I can't even use a camera man! Anyway, I've an old amp that's new to me and I am not certain I know what a particular feature is.

It's an early '70-'72 West Fillmore. On the rear panel there are a pair of jacks that read "Preamp In" and "Preamp Out". I'm guessing I could use this to insert an external preamp to bypass the amps preamp. However, a friend told me that those early amps were often slaved together for more power and that's what these jacks were used for.

I've gotten absolutely no help from contacting West Amps. They answered my eMails, but essentially they said they couldn't help me with anything and good luck.

Do any of you know for sure what these jacks are for?

BTW, This amp was in sad working order when I received it, but I finally got it back from Savage Audio a week or so ago and man... This thing is a beast! It sounds absolutely incredible. I've been going SS since the mid '80s or so and man, am I happy I went back.

Thanks

emjazz · #2 11-17-2010, 10:04 PM

I'm sorry I can't help you, but I just wanted to add that that's a killer amp! Have fun with it!

LongHairFreak · #3 11-17-2010, 10:44 PM

Thanks man. Been fun so far. It's got depth I've not heard from my rig(s) in a long while. I've even taken a couple pedals out of my line-up; I just feel this amp doesn't need them.

emjazz · #4 11-17-2010, 10:52 PM

A friend of mine owns one. I got to record someone's record with it once. It sounded so good.

JimmyM · #5 11-17-2010, 11:12 PM

Quote:

Originally Posted by LongHairFreak

Hey Folks

I know I'm breaking unwritten laws here by not posting pics, but please give me a break this time around.I mean, I can't even use a camera man! Anyway, I've an old amp that's new to me and I am not certain I know what a particular feature is.

It's an early '70-'72 West Fillmore. On the rear panel there are a pair of jacks that read "Preamp In" and "Preamp Out". I'm guessing I could use this to insert an external preamp to bypass the amps preamp. However, a friend told me that those early amps were often slaved together for more power and that's what these jacks were used for.

i would think it would work both ways. if you're slaving amps, you'd want one pre to control everything, so it would have to defeat the internal pre if you go preamp in, right?

now you need to get one of those aluminum guitars like mark farner used.

bigntasty · #6 11-17-2010, 11:35 PM

I've never owned a West amp or cab, but your question got me wondering about the preamp in / out. Here's a link to an active West forum with what sounds like some educated owners. Maybe you could inquire there. It's toward the bottom of the page.

http://benjefferies.com/2009/09/19/w...iers/#more-149

sconix · #7 11-18-2010, 09:55 AM

The schematics on West's site are pretty clear. What you have in todays lexicon are 'preamp out' and 'power amp in' jacks. The pre-out will leave the internal power amp connected. The power-in jack disconnects the preamp feed internally. Making it easy to slave off of another amp's pre-out.

LongHairFreak · #8 11-18-2010, 01:53 PM

todays lexicon are 'preamp out' and 'power amp in' jacks. The pre-out will leave the internal power amp connected. The power-in jack disconnects the preamp feed internally. Making it easy to slave off of another amp's pre-out.

Hmmm. That's rather confusing, but I guess I should first get someone to read the rear panel again to make sure they are pre/pre jacks as opposed to power/pre jacks.

If the latter though, should I then be able to do something akin to...?
Feed amp#1 into the Power In of amp#2 (the West); then feed amp#2s Preamp Out into the Power In of amp#3? Thereby using a collective power of all three amps while only using amp#3s preamp functions? (I would have no reason to do this; I just want to know how those jacks work).

If the West in fact does have pre/pre jacks, would I be able to...?
Plug an external preamp (my LowEnd True Voice?) into these jacks like a typical loop? Thereby bypassing the West's internal preamp with the LETV, while using it's power? (A more likely thing for me to do).

sconix · #9 11-18-2010, 03:37 PM

It's NOT confusing. The 'preamp in' on the back of the West is really 'power amp in'. According to schematics anyway. 40 years ago with hippies hooking this stuff up this probably made sense, today it doesn't. This link if translated in Google refers to the 'mystery jacks'. http://homepage3.nifty.com/stvb/mel/west_7.htm The preamp has a very high ouput impedance, so chaining a bunch of stuff off it may not be a great idea. You certainly can use te LowEnd pre, an Alembic whatever into the PREAMP IN ( power amp input ) with no problems.

LongHairFreak · #10 11-18-2010, 03:53 PM

Interesting. I just may try the LETV in there. I've got to believe a 6SN7 would push the 6550s differently than a pair of 12A*7s.

Thanks for the clarification Sconix.
Thanks to you others too.

billfitzmaurice · #11 11-18-2010, 05:44 PM

Quote:

Originally Posted by LongHairFreak

Do any of you know for sure what these jacks are for?

Today they'd be called an effects loop.

LongHairFreak · #12 11-18-2010, 09:35 PM

Really! Is it that simple? I mean, doesn't an effects loop blend with the internal preamp? Whereas I assumed...I mean figured...this pre-in/pre-out thing may actually replace the internal preamp.

JimmyM · #13 11-18-2010, 10:20 PM

you know, there's one way to tell for sure...plug in a preamp and see what happens. and then try an effect like it's a loop. it's not going to damage anything unless you try to plug in a speaker to it.

LongHairFreak · #14 11-18-2010, 10:27 PM

Ahh. The direct approach!
I should've figured it wouldn't hurt to try.
Thanks

JimmyM · #15 11-18-2010, 10:32 PM

lol! well i can understand...tube amps are fussy about some stuff. but in this case, i think you're in the clear.

billfitzmaurice · #16 11-19-2010, 06:47 AM

Quote:

Originally Posted by LongHairFreak

.this pre-in/pre-out thing may actually replace the internal preamp.

You could plug an external pre into the power amp in, bypassing the internal pre. You also could plug the pre out into an external power amp. But you can do the same thing with the effects send/receive on an amp so labeled. The circuits are the same, only the labels are different.

thumpbass1 · #17 11-19-2010, 08:38 AM

Congrats on your new vintage amp. Go find a copy of Grand Funk's first double live album and rejoice in Mel Schacher's fat, growling, and punchy, lead bass, stank tone. He helped to sell those West amps to those who were lucky enough to have a music retailer that carried them. You have a great amp there. Enjoy.

LongHairFreak · #18 11-19-2010, 09:15 AM

Thanks Thumpbass1. Great recommendation too. Though I have been listening to GFR's Live Album ever since I was...13?...soon after it came out anyway. It's Mel's influence that got me going on the bass.

Matt Dean · #19 11-19-2010, 10:32 AM

Mel... now that's a rig of doom!

thumpbass1 · #20 11-20-2010, 07:05 AM

Quote:

Originally Posted by LongHairFreak

Thanks Thumpbass1. Great recommendation too. Though I have been listening to GFR's Live Album ever since I was...13?...soon after it came out anyway. It's Mel's influence that got me going on the bass.

Wow! I was about the same age when that album came out, maybe 14 years old. I was learning to play guitar, but Mel really inspired me to become a bass player instead. Today I do both, but bass is my first love, and I blame Mel Schacher for most of it. Jack Bruce, Felix Pappalardi, McCartney, Larry Taylor and Barry Oakley also helped.