Opinions on Pull Boost Deluxe Reverb

El Capitan · August 13th, 2006, 03:50 PM

I just picked up a "beat to heck" Pull Boost Deluxe Reverb.
All original parts, never been serviced, Tubes falling out, no tolex, etc.
It sounds ok.
At this time I guess I am wanting to make "The Ultimate Deluxe Reverb".
I got this thing cheap enough.
I bought a set of tubes from JJ, and a NOS JAN 5U4GB rectifier, I'm gonna recap it of course. I have a D120F that I'm gonna install.

What suggestions do you guys have for "improving" this amp besides the usual service work?
Do you think that this later design might have more headroom than a BF circuit? That would be OK with me...
I guess I could answer that last question after I cap it. Right now it REALLY needs some work before I turn it on....

trag-o-caster · August 13th, 2006, 06:17 PM

I had that 77 pull boost DR and it was my #1 for such a long time - even before I had Tim Swartz BF it, disengage the pull boost, and re-cap it. I put a Weber 12F150 in it as soon as I got it.

I understand that as long as you don't pull the boost, it's almost BF. They didn't change these as much as they did the bigger Fenders. Unfortunately that pull boost is involved with the reverb 12AT7 somehow, and even with the pull boost off - it causes extra stress on that tube for some reason. Hopefully someone more knowledgeable than myself will explain this better than I can.

Tremo · August 13th, 2006, 08:43 PM

Yeah, on those pull-boost amps, they frequently EAT the 12AT7 verb drivers. Run them hottern'hell. They die, sometimes causing chain reaction failures. IMO, best thing for a pull-boost amp is to remove that crap entirely, and put everything back to blackface specs. Of course you lose the boost function, but it sounds crappy anybody and I don't know anyone who actually uses it. If you want high gain distortion, buy a Mesa.

Just clean it up, service it and you should be good.

El Capitan · August 14th, 2006, 12:23 AM

Thanks fellas
I was wondering whether or not to remove that Pull Boost circuit.
It does sound like crud!

Tremo · August 14th, 2006, 01:08 AM

Get 'er dun!!!

trag-o-caster · August 14th, 2006, 02:56 PM

Is it my imagination or has the prices of SFDR's kinda leveled off? Possibly even gone down??? I've read about a couple of people getting them from GC - of all places - for less than $600.

I paid about $800 for my 77, which was in like new condition, w/original speaker, etc. and I got exactly $800 for it on ebay. So, they haven't exactly jumped up in price like I expected them to.

No matter. I bought 'em to use 'em - not to turn for a profit

El Capitan · August 14th, 2006, 08:18 PM

Ya, I noticed they aren't going up very quickly in value.
But like you say, I bought it to use it.
I got this one for $280 in Austin. it looks like total crap though. I thought it would be great since I got it so cheap and it needs so much work to try and make it the "ultimate" or "tone standard" in Deluxe Reberbs...

Hey, we can all have dreams! HA

trag-o-caster · August 14th, 2006, 09:32 PM

Well that's the good thing about the old SF (and before) Fenders - no matter how banged up they are, you can get right in there and get 'em going again - just like an old Chevrolet or something.

Pierce · August 15th, 2006, 08:48 AM

it's amazing the difference between the lead dress on a pull boost dr and a BF (heck even early SF) it seems they used one length of wire for every connection... it's very BUSY in there

Drak · August 15th, 2006, 11:32 AM

I bought my two SFDR's years ago the exact same way (cheap and dogged) with the exact same intentions (i.e. beat up so I could do some mods w/o feeling guilty)

They both needed recovers, so I did one in a nice rough creme/oxblood combo, and since the baffle was also busted, made a 2-10 out of it with a pair of Weber P-10N's (16 ohms/ea.).

The other I put an old Electro Voice alnico 12" SRO in it, and I love 'em both to death, so I t5hink you did great!

Mitch Roberts · August 15th, 2006, 11:42 AM

As mentioned, the lead dress is always pretty messy, but if you know what you are doing, you can easily clean that up. Check the resistor values in the phase inverter circuit, as those are usually different in s SF. The coupling cap leading into the phase inverter circuit carries all the prior tone signal in, and it can be very critical. They are usually .01mfd on SF, instead of .001 on most BF. While this might sound pretty good a lower volumes (increased bass) it makes for more mud at higher volumes. I once worked on a Super Reverb that just didn't sound right. I finally thought to change that cap and it really transformed the amp. Easy enough to try for yourself.

Paul in Colorado · August 15th, 2006, 03:50 PM

What you could do with the Pull Boost is to have a couple of different cap values for the "mids" and pull the knob to change the value. As I remember they're hardwired like a preamp with a mid knob set on 7.

Tremo · August 15th, 2006, 04:22 PM

Lead dress in the later SFs is a real rat's nest mess. I do recommend going in and cleaning it up, shortening wires as needed.

El Capitan · August 16th, 2006, 08:57 PM

Man,
Thanks for all the help!
I will be sure to post pics of my "rescue mission" when I'm done with it..
Now,
Off to Tonecraft for some supplies/advice....
El

August 13th, 2006, 03:50 PM	#1 (permalink)
El Capitan Tele-Holic Join Date: Jul 2003 Location: AUSTIN, Tejas! Posts: 810 2 Photos	Opinions on Pull Boost Deluxe Reverb I just picked up a "beat to heck" Pull Boost Deluxe Reverb. All original parts, never been serviced, Tubes falling out, no tolex, etc. It sounds ok. At this time I guess I am wanting to make "The Ultimate Deluxe Reverb". I got this thing cheap enough. I bought a set of tubes from JJ, and a NOS JAN 5U4GB rectifier, I'm gonna recap it of course. I have a D120F that I'm gonna install. What suggestions do you guys have for "improving" this amp besides the usual service work? Do you think that this later design might have more headroom than a BF circuit? That would be OK with me... I guess I could answer that last question after I cap it. Right now it REALLY needs some work before I turn it on.... __________________ virescit vulnere virtus

August 13th, 2006, 06:17 PM	#2 (permalink)
trag-o-caster Friend of Leo's Join Date: Mar 2003 Location: Flushing, Michigan Posts: 4,558	I had that 77 pull boost DR and it was my #1 for such a long time - even before I had Tim Swartz BF it, disengage the pull boost, and re-cap it. I put a Weber 12F150 in it as soon as I got it. I understand that as long as you don't pull the boost, it's almost BF. They didn't change these as much as they did the bigger Fenders. Unfortunately that pull boost is involved with the reverb 12AT7 somehow, and even with the pull boost off - it causes extra stress on that tube for some reason. Hopefully someone more knowledgeable than myself will explain this better than I can. __________________ Timothy Jon Lamb

August 14th, 2006, 12:23 AM	#4 (permalink)
El Capitan Tele-Holic Join Date: Jul 2003 Location: AUSTIN, Tejas! Posts: 810 2 Photos	Thanks fellas I was wondering whether or not to remove that Pull Boost circuit. It does sound like crud! __________________ virescit vulnere virtus Last edited by El Capitan; August 14th, 2006 at 01:35 AM.

August 14th, 2006, 02:56 PM	#6 (permalink)
trag-o-caster Friend of Leo's Join Date: Mar 2003 Location: Flushing, Michigan Posts: 4,558	Is it my imagination or has the prices of SFDR's kinda leveled off? Possibly even gone down??? I've read about a couple of people getting them from GC - of all places - for less than $600. I paid about $800 for my 77, which was in like new condition, w/original speaker, etc. and I got exactly $800 for it on ebay. So, they haven't exactly jumped up in price like I expected them to. No matter. I bought 'em to use 'em - not to turn for a profit __________________ Timothy Jon Lamb

August 14th, 2006, 08:18 PM	#7 (permalink)
El Capitan Tele-Holic Join Date: Jul 2003 Location: AUSTIN, Tejas! Posts: 810 2 Photos	Ya, I noticed they aren't going up very quickly in value. But like you say, I bought it to use it. I got this one for $280 in Austin. it looks like total crap though. I thought it would be great since I got it so cheap and it needs so much work to try and make it the "ultimate" or "tone standard" in Deluxe Reberbs... Hey, we can all have dreams! HA __________________ virescit vulnere virtus

August 13th, 2006, 08:43 PM	#3 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,735	Yeah, on those pull-boost amps, they frequently EAT the 12AT7 verb drivers. Run them hottern'hell. They die, sometimes causing chain reaction failures. IMO, best thing for a pull-boost amp is to remove that crap entirely, and put everything back to blackface specs. Of course you lose the boost function, but it sounds crappy anybody and I don't know anyone who actually uses it. If you want high gain distortion, buy a Mesa. Just clean it up, service it and you should be good.

August 14th, 2006, 01:08 AM	#5 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,735	Get 'er dun!!!

August 14th, 2006, 09:32 PM	#8 (permalink)
trag-o-caster Friend of Leo's Join Date: Mar 2003 Location: Flushing, Michigan Posts: 4,558	Well that's the good thing about the old SF (and before) Fenders - no matter how banged up they are, you can get right in there and get 'em going again - just like an old Chevrolet or something. __________________ Timothy Jon Lamb

August 15th, 2006, 08:48 AM	#9 (permalink)
Pierce Tele-Meister Join Date: Mar 2003 Location: skull island Posts: 471	when you pull the chassis.. it's amazing the difference between the lead dress on a pull boost dr and a BF (heck even early SF) it seems they used one length of wire for every connection... it's very BUSY in there

August 15th, 2006, 11:32 AM	#10 (permalink)
Drak Tele-Meister Join Date: Mar 2003 Location: DC 'Burbs Age: 47 Posts: 447	I bought my two SFDR's years ago the exact same way (cheap and dogged) with the exact same intentions (i.e. beat up so I could do some mods w/o feeling guilty) They both needed recovers, so I did one in a nice rough creme/oxblood combo, and since the baffle was also busted, made a 2-10 out of it with a pair of Weber P-10N's (16 ohms/ea.). The other I put an old Electro Voice alnico 12" SRO in it, and I love 'em both to death, so I t5hink you did great!

August 15th, 2006, 11:42 AM	#11 (permalink)
Mitch Roberts Tele-Meister Join Date: Mar 2003 Location: NYC Posts: 433	As mentioned, the lead dress is always pretty messy, but if you know what you are doing, you can easily clean that up. Check the resistor values in the phase inverter circuit, as those are usually different in s SF. The coupling cap leading into the phase inverter circuit carries all the prior tone signal in, and it can be very critical. They are usually .01mfd on SF, instead of .001 on most BF. While this might sound pretty good a lower volumes (increased bass) it makes for more mud at higher volumes. I once worked on a Super Reverb that just didn't sound right. I finally thought to change that cap and it really transformed the amp. Easy enough to try for yourself. __________________ I think, therefore I jam.

August 15th, 2006, 03:50 PM	#12 (permalink)
Paul in Colorado Friend of Leo's Join Date: Mar 2003 Location: Fort Collins, CO Age: 55 Posts: 4,318 3 Photos	What you could do with the Pull Boost is to have a couple of different cap values for the "mids" and pull the knob to change the value. As I remember they're hardwired like a preamp with a mid knob set on 7.

August 15th, 2006, 04:22 PM	#13 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,735	Lead dress in the later SFs is a real rat's nest mess. I do recommend going in and cleaning it up, shortening wires as needed.

August 16th, 2006, 08:57 PM	#14 (permalink)
El Capitan Tele-Holic Join Date: Jul 2003 Location: AUSTIN, Tejas! Posts: 810 2 Photos	Man, Thanks for all the help! I will be sure to post pics of my "rescue mission" when I'm done with it.. Now, Off to Tonecraft for some supplies/advice.... El __________________ virescit vulnere virtus