Just in: 67/68 Pro Reverb

[Scott_F]

It's got the blackface circuit AA165, but it's got the silverface on it. The trannies are all 66 models. No rust to speak of on the PT. I'm not sure if this is a 67 or 68. The Fender field guide says 68 were the first silverfaces, but the circuit is definitely 65-67. The seller thought it was a 68, but he also thought it had a master volume! Tail logo was another clue. Has what I can only guess are very old tubes in it, RCA 6L6GC's, a Mullard 5AR4, and a mixture of RCA and Telefunken preamp tubes. Tubes are quiet and the amp sounds pretty darn good. If the tubes last any time at all, even used they were worth at least 250 bucks.

Grill clothe in the front is kinda ripped, but more scraped than actually torn. It looked worse in the pictures. Tolex is in decent shape for a 36 year old amp.

The reverb cables are fairly shot, the reverb tank may or may not be working. I'm having a hard time telling. took the tank out of the bag and it's spotless on the inside, the springs seem to be moving/suspended if that makes sens. I'm going to slap some new cables in there. I tried re-soldering one connector, but it's shot.

Vibrato works really well. No footswitch came with it, but I have a new one with the correct connectors.

Speakers are mixed, one is an orange label Utah, one is a blue label Fender, both fart like a weekend of a wheat beer binge.

I wired two Red Fangs at 4 ohms and ran the amp that way and the farts disappeared. I'm not sure those are the right replacements, but it's a start.

Pots need to be cleaned, 3 prong cord needs to be installed, and I'm sure I'm facing a cap job. I plan on opening up the chassis later. I'm looking forward to doing the work myself. I thought I might have to "blackface" this thing. I guess the tube chart could be wrong.

Amp just sounds really good as it is now (minus the reverb).

 

[Falstaff]

Re: Just in: 67/68 Pro Reverb

Welcome to the club. That's a great score and it's gonna sound wonderful as is. Wimpy tranny (that seems to be the conventional wisdom) or not, they are great amps and sound like a Fender should. I was playing mine with a Strat and an Analogman Juicer the other night and I couldn't imagine anything sounding better.

Did you get the HAO pedal yet?

 

[Curly]

Re: Just in: 67/68 Pro Reverb

sounds good ...

get some caps from Mouser, etc

i didn't know those had wimpy trannies, but if you push 'em, what's that mean?

Do they sound good or not?

anyway, I htought '68's had the alum. trim piece - is that right?
doesn't really matter, 'cos you know it's blackface inside!

 

[Falstaff]

Re: Just in: 67/68 Pro Reverb

sounds good ...


i didn't know those had wimpy trannies, but if you push 'em, what's that mean?

Do they sound good or not?

Sorry...that was my point. They sound really good! Some guys put in Bassman trannies, etc., but I think they sound wonderful as is. They are just sort of the dark horse of the Fender combos. So boobs like me can afford them!

Got any pics, Scott?

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

Curly, it has the aluminum edge around the grilclothe. someone called that a drip edge, I think one time. I won't really know about the insides until I crack it open. The chart does say AA165, so hopefully it's accurate.

I just ordered some new reverb cables and a 3 spring accutronics tank from Torres.

I'm not sure about the filter caps. As long as they are not bubbling on the ends, and the amp is quiet, maybe I'm okay? Not sure.


Falstaff, I think I might have overpaid for it, but I'm happy that it is what I thought it was. ($650) One year earlier with a blackface and they go for 2 grand now. Gerald Weber recommends putting a 4 ohm blackface-era bassman OT in them. I'll have to keep my eyes open for one. But, it ain't broke, so I'm not going to go too nuts.

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3731213180&sspagename=STRK:MEWN:IT&rd=1


looks worse in the pics than in real life.

 

[Falstaff]

Re: Just in: 67/68 Pro Reverb

I think you done good, Scott! I have seen them on gbase for close to a grand. And those drip edge amps really have a unique mojo. The good thing is that you can fool with a SF a bit and not end up shooting yourself in the foot if you ever want to sell it.

The guy I take mine to suggested I do a mod to get rid of the negative feedback loop and put an on/off pot in the vibrato circuit, but I'm sorta afraid to because I like things simple (the fewer options the better for a dummy like me) and because its a BF. Both mods would be reversible, so maybe I should try them...I think KMC has a BF PR with a more robust tranny, maybe he can advise us. I'd love to hear what someone who has had one a long time thinks.

Rock on and enjoy it!

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

Gerald Weber's book lists 10 mods you can do. One of them is that he suggests that you just clip the tremelo wire completely and tape off the end (so you can reattach later) and it's supposed to give the amp a bit more volume. The trem circuit bleeds off a bit of signal at all times.

There are several other mods, including basically doing away with the normal channel completely.

2. He also suggests increasing the value of the feedback resistor from 820 to 1500 ohms in order to have less signal going back into the amp. Increases volume and harmonics. You could just put an off/on switch there as well I guess.

3.Thicken the tone by increasing hte coupling cap value on the phase inverter
to a 0.02 mfd 400v cap.

4. change the ot tranny to a bassman.

5. improve gain by taking out the v1 tube in the normal channel, effectively killing it off.

6. replace the 12AT7 PI to a 12AX7 to increase gain and dynamic response

7. change speakers

8. good NOS tubes

9. talks about elimating the normal channel part of the Phase inverter series something or another

etc. etc.

Instead of your tech putting an on/off switch on the negative feedback loop, i'd be interested in putting a variable resistor in there instead, one that would let you go from 820 to about 2000 ohms. that way you could dial it in. Or a three way toggle with an 820, 1500 and an option to bypass...

cool stuff.

 

[seafoamer]

Re: Just in: 67/68 Pro Reverb

I have an early 1968 Pro Reverb with the Drip edge and the black lines on the face. I bought it 2 yrs ago in "never left the house" condition. Mine wasn't black face, but being so early in 68, it wasn't much at all to BF it, so I let my tech at it. Cool amp! if I used mine more I would change the stock speakers definately.

Congrats on u'r score. & I think u'r price was nice.

 

[Curly]

Re: Just in: 67/68 Pro Reverb

yeah, Scott ... the drip faces are some of the best deals around, 'cause they're virtually BF inside

I'm sure you'll play it plenty before doing any mods, but good tubes, a nice bias, and maybe speakers might be all she needs

I don't know about the other mods, but I tried a 12AX7 PI and didn't like it as much as stock

I think Mojo has some aged grill cloth for that, too ... if they don't, someone else will, if you're going to replace it

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

Definitely needs a cap job. I popped the hood and they are originals. Not very noisy, but they just look fried to me. Unbelievably neat inside. Makes me appreciate the amount of space to work in. Those Tweed Deluxes we built, Curly, were difficult for my ham fists to get inside and work. This thing has acres of room inside.

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

I've got a green back and a v30 that I pulled out of my other amp. I'll probably slap those inside immediately.

 

[Kent S.]

Re: Just in: 67/68 Pro Reverb

Cool score Scott, I'd have to say that replacing the tremolo intensity pot with one that has an on/off switch at the low side is a nice mod as it still lets you use your tremolo if desired. I don't think I'd do away with the negative FB totally as that helps to balance out the frequency response of the output tranny (among other things), I like the idea of making it variable though ...
Not sure about yanking a tube to increase gain? A cool mod is to keep the normal channel and either use it as an extra preamp ...ala Boogie (complete with it's own tone controls) ... OR ... There's is a mod that lets that channel have reverb also, and then you could revoice that channel to be warmer (or whatever your tastes) ... you could then switch between channels with something like a BOSS LS-2 line selector, even run two sets of pedals, if your into that. Depends how much you want to change it though, so food for thought.

 

[Curly]

Re: Just in: 67/68 Pro Reverb

I've got a green back and a v30 that I pulled out of my other amp. I'll probably slap those inside immediately.

yikes! that'll smoke!

as long as it doesn't have any ghost notes, it'll sound great

 

[54stratlover]

Re: Just in: 67/68 Pro Reverb

I've got a green back and a v30 that I pulled out of my other amp. I'll probably slap those inside immediately.

that is the same speaker combo I use in my twins, and I love the sound. I have the jensen reissues in another twin, and am not sure i am into that sound. little more headroom, and very clean. takes alot to break them up.

Regarding some of the mods above, with my 70's twin, I have a pot on the trem circuit that takes it out of the circuit when dialed all the way to counterclockwise. Its called a trem bypass. The fellow that did the work on my amps did a mod to the left channel (the one that people rarely use) that makes is sound bassmanish, or jtm 45ish. If you are interested, I can find out more about it, or give you the guys name and #.

I have to confess, I am a electronics retard.

 

[54stratlover]

Re: Just in: 67/68 Pro Reverb

Cool score Scott, I'd have to say that replacing the tremolo intensity pot with one that has an on/off switch at the low side is a nice mod as it still lets you use your tremolo if desired. I don't think I'd do away with the negative FB totally as that helps to balance out the frequency response of the output tranny (among other things), I like the idea of making it variable though ...
Not sure about yanking a tube to increase gain? A cool mod is to keep the normal channel and either use it as an extra preamp ...ala Boogie (complete with it's own tone controls) ... OR ... There's is a mod that lets that channel have reverb also, and then you could revoice that channel to be warmer (or whatever your tastes) ... you could then switch between channels with something like a BOSS LS-2 line selector, even run two sets of pedals, if your into that. Depends how much you want to change it though, so food for thought.

The trem bypass is a must have in my book. really warms up the tone an a great sounding channel anyway. I have the mod with the reverb on teh left channel, and it has been revoiced to the bassman, jtm45 sound. I love the mod. I used to consider the left channel useless for the most part. Now I use a ernie ball volume/pan pedal and switch between the two seemlessly

 

[Falstaff]

Re: Just in: 67/68 Pro Reverb

The trem bypass is a must have in my book. really warms up the tone an a great sounding channel anyway. I have the mod with the reverb on teh left channel, and it has been revoiced to the bassman, jtm45 sound. I love the mod. I used to consider the left channel useless for the most part. Now I use a ernie ball volume/pan pedal and switch between the two seemlessly

That's great info, 54. I have heard of that mod but never knew anyone that actually had it. I had the Boogie Mod (cascading gain) put into the left channel of a DR I had. It was nice but a bit over the top; I'm sure the one you describe is more organic. And the trem bypass sounds like a must, thanks for writing that. The dude I took it to described it as something like "just allowing you to access something that's already there."

Scott, one thing you can do (you probably already know this) is pull the normal channel preamp tube; that makes the other preamp tubes run a bit hotter, just when you are using the reverb channel, obviously!

Kent, I am interested in making the NFB loop variable as well, that might be fun for dialing in different sounds for different situations. The tech I took it to suggested that I just install a (removable) switch to either put it in or out, but maybe a three way switch could find some medium in there as well.

Rock on!

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

the guy I bought the amp from is refunding 75 bucks for the reverb "repair"

That's cool. I wasn't expecting anything since he's been such a lamer on communications, wouldn't send me a tracking number, etc.,.

 

[Jeff_H]

Re: Just in: 67/68 Pro Reverb

Cool score Scott....It'll be nice to have a vintage Fender amp sitting around to mess with. Nice score on the NOS tubes as well!

 

[Scott_F]

Re: Just in: 67/68 Pro Reverb

Well, they're not NOS, but I'm guessing I ought to get long life out of the rectifier (those old Mullards last forever) and the preamp tubes ought to last a long time as well. The power tubes are questionable. I'm going to pop that set of KT66HPs I have sitting in the drawer into it. That ought to be my best way of gauging how good/bad the RCA 6L6GC's are.