My first tube amp, need help...

kfa888 · Feb 21, 2006

I got a old "the Fisher" stereo tube amp from a fellow AKer this last weekend. Supposedly it was bad and turned on but just hummed. I pulled it out of the console today to get it repaired and thought I would fire it up to see what was up with it. I hooked it up to some test speakers and a CDP. To my surprise it sounds fine, works out of both channels and is clear as a bell.

So what do you think the ohm rating is for the speakers so I can hook up some good speakers? Also anyone know the WPC of this thing? And, is hooking up a CDP OK to do? It has a phone input form the original TT and another set I am guessing is a line in which I hooked the CDP to and it work fine. I just know nothing about this stuff and want to understand.

thanks in advance.

Kelly

Charivari · Feb 21, 2006

Aw, I want it back now. :thmbsp: Just kidding of course, though I am amazed that it is working. Sure wasn't here, must've been that highly specialized cryo treatment I put it through (or the vibration of the trip). You'll want to pull that masking tape off of those tubes; I was told this was a 6BQ5 amp, but the tubes tested as shorted on my Heathkit TC-2 at that setting. Since it's not working, you might as well remove my labels (put on to keep from mixing good tubes with bad) before the adhesive bakes on.

Oh, for the record and to help others, it's The Fisher Promenade.

- JP

cruisaire · Feb 21, 2006

Pretty!!!!

Dynacophil · Feb 21, 2006

Hi
looks like el84/gbq5 > could be 15W/channel
Helge

jpdylon · Feb 21, 2006

The amp is most likely going have taps for 8 ohm speakers. Most speakers during this time in consoles were 8 ohms. Some were 16 but most were 8. YOu can measure the resistance of the secondary windings of the output transformers. That should tell you whether they are 8 or 16 ohm. THe winding impedance determines what kind of speakers you can connect to the amp.

surfer · Feb 21, 2006

Should sound good

By the way could you tell me what those speakers are in your photos? The ones with tan cones?
Thanks

kfa888 · Feb 21, 2006

surfer said:
By the way could you tell me what those speakers are in your photos? The ones with tan cones?
Thanks

POS "Sonic" brand which as far as i can tell a pioneer entry level speaker.

Kegger · Feb 22, 2006

I think JP got rid of a very nice amp with a quad of Bugle Boy EL84/6BQ5 output :banana:

tubes (great tubes) and the amp should put out about 12watts a channel. Some
tube testers are funky with certain tubes, I've gotten lucky with mine and it does
test everything with very reliable results. Try an EL84 setting if you have one.

Would make for a very nice amp to your full range utahs in a transmission line or a
folded horn setup with a super tweeter uptop, or whatever you come up I'm sure
will be nice. :music:

From the looks underneeth it seems to have had a recent tune up with the orange
drops and just the cleeness of it. :thmbsp:

8ohm speakers should work fine. :thmbsp:

Squidward is going to be jelous! :yes:

Urizen · Feb 22, 2006

Very nice. With a little TLC and some mods, such as new rca inputs, speaker terimnals and a case, it could be a killer amp. I have always loved the sound of EL-84's in guitar amps I have owned. That point to point wiring is sweet.

Charivari · Feb 22, 2006

Kegger said:
I think JP got rid of a very nice amp with a quad of Bugle Boy EL84/6BQ5 output
tubes (great tubes) and the amp should put out about 12watts a channel. Some
tube testers are funky with certain tubes, I've gotten lucky with mine and it does
test everything with very reliable results. Try an EL84 setting if you have one.

Had I known, I would've stuck the Holland label Amperex tubes in my Fisher, but I didn't want to risk unlabeled "shorted" tubes in a $400+ amp.

Ah well, I'm glad of where it's ended up and more so that it does work afterall (still has me confused why that's the case, maybe the cold and vibration of the trip in the back of my truck fixed it).

Kegger said:
Squidward is going to be jelous! :yes:

Even more so if he knew the very low price Kelly got this amp for. :thmbsp:

- JP

Andyman · Feb 22, 2006

Charivari said:
I was told this was a 6BQ5 amp, but the tubes tested as shorted on my Heathkit TC-2 at that setting. Since it's not working, you might as well remove my labels (put on to keep from mixing good tubes with bad) before the adhesive bakes on.

Oh, for the record and to help others, it's The Fisher Promenade.

- JP

FWIW, two of those tubes w/o tape are Amperex Bugle Boys and command a decent price themselves. I'd test them on another tester and treat them carefully so the lettering doesn't smudge; a pair of those could finance a new matched quad of EH/sovtels/Teslas.

Also, that amp MAY require the matching preamp tuner to operate. I recently sold a similar Fisher amp (A-440??) and it had the cathode biasing run through the preamp 12AX7s,so if your's doesn't work, that could be the issue and not bad tubes.

just a thought.......

Kegger · Feb 22, 2006

Andyman said:
Also, that amp MAY require the matching preamp tuner to operate. I recently sold a similar Fisher amp (A-440??) and it had the cathode biasing run through the preamp 12AX7s,so if your's doesn't work, that could be the issue and not bad tubes.

just a thought.......

Did I miss something? I thought it was working fine?

Kegger · Feb 22, 2006

Charivari said:
Had I known, I would've stuck the Holland label Amperex tubes in my Fisher, but I didn't want to risk unlabeled "shorted" tubes in a $400+ amp.

Ah well, I'm glad of where it's ended up and more so that it does work afterall (still has me confused why that's the case, maybe the cold and vibration of the trip in the back of my truck fixed it).

Even more so if he knew the very low price Kelly got this amp for. :thmbsp:

- JP

I hear yu on both acounts and understand completely!

Andyman · Feb 22, 2006

Kegger said:
Did I miss something? I thought it was working fine?

Nope, looks like I did, like the "clear as a bell" part.

Kegger · Feb 22, 2006

Andyman said:
Nope, looks like I did, like the "clear as a bell" part.

LOL!

kfa888 · Feb 22, 2006

Thanks for the help guys and keep it coming. I will for sure keep the original tube pre, it sounds great and the tone controls work better than any I have used before, huge range from deep bass to very little, bright to dark. I like it.

As far as the tubes looks like amprex and mullard. the lettering is pretty much gone but some of it you cam make out. there is a sticker on it and it was serviced right here in Portland Oregon not to long ago.

JP, I think the main issue is the multi pin inner connect and the two RCA's inter connects between the pre and amp. I am also having issues with stereo operation which I think might be the RCA pre to power amp. I'm going to look at it more tonight.

the plan is to get it serviced, make sure it is working right and measures right and then mount it back in the cool console it came from. I will refinish that and yard the TT and use that area for CD's. I'll post more pix tonight.

I ran it for a while on those little RS full ranges to make sure it was not going to blow speakers and then bit the bullet and fed it to my Wharfedale W90's, sweet sound and seems to match well. This is going to be fun!

Kegger, you know I'm already thinking about running those Utahs, talk about minimalist!

thanks guys, especially you JP

kfa888 · Feb 23, 2006

Just took the cover off the pre to look inside, man a lot more stuff in there than i was expecting. what a jungle. Looks very clean.

JP what were you thinking?

kfa888 · Feb 23, 2006

A few more of the amp side...

Charivari · Feb 23, 2006

kfa888 said:
JP what were you thinking?

Good question. I guess I just gave in to all those comments you made about wanting to try out tubes with your Wharfedales. That and I did stub my toes against that console enough times to hold some dislike for it. I say, attribute it to momentary insanity.

Those pics reveal a good candidate for recapping. Pick up a Sam's Photo Facts sheet for the console and order some good IEC polyprops from Antique Electronics Supply and enjoy the improvement in the sound. Just watch the order when it comes in, I ordered some polyprops from them for my Fisher SA-16 and they sent me a mix of polyprops and not as good and cheaper polyeths. The common recommendation with older tube amps is to replace the coupling caps with polyprops. There are usually a couple of 0.022μfd on each of the output tubes that you probably can go ahead and upgrade to or 0.033μfd. You can read about my experiences in this, which should relate to your similar Fisher 6BQ5 amp in this thread.

Try getting ahold of Jimmydee. He's done quite a few Fisher console restorations including another Promenade like yours and is usually willing to help a newb to the field. While he only sporadically visits AK, you should be able to find him at AA.

Good luck with the amp, but try to tone your bragging down a bit. I'm already grumbling enough about the deal. :thmbsp:

- JP

kfa888 · Feb 23, 2006

Charivari said:
Good luck with the amp, but try to tone your bragging down a bit. I'm already grumbling enough about the deal. :thmbsp:

- JP

Not bragging at all, I'm stoked it works and is so clean. Much appriciated. :thmbsp:

BTW I did deliver speakers to Seattle for you, am storing some speakers for you and let you keep the HPM's

My first tube amp, need help...

Addicted Member

Attachments

Fighting Naïve Realism

PGA and Rainwater!

I ain't Phil, I'm 'phile

non-active member...

New Member

Addicted Member

R.I.P. 1/12/1966 - 6/1/2017

Lunatic Member

Fighting Naïve Realism

Scroungus Stereophilus

R.I.P. 1/12/1966 - 6/1/2017

R.I.P. 1/12/1966 - 6/1/2017

Scroungus Stereophilus

R.I.P. 1/12/1966 - 6/1/2017

Addicted Member

Addicted Member

Attachments

Addicted Member

Attachments

Fighting Naïve Realism

Addicted Member