Fender Pro Reverb is done... for now...

[Scott_F]

Okay, so I put in all new caps. I mean all of them. Many of them were just crumbling. This is that first year silver face (drip edge) 68 Pro Reverb. It was the bastard child of a blackface circuit AA165 and an overzealous silverfaced engineer. It was pretty silver faced in terms of the circuit, but it was stamped AA165 all over the place. The trannies were all 67 and 68 vintage.

So, here's what I did.

1. Completely new caps, all of them. Gerald Weber advised me to increase the values of a few of them and I went with his expert advice. (Nice dude!)

2. Went back and put in new resistors in the phase inverter and turned it completely back to the AA165 Blackface values.

3. Got rid of a bunch of the silver faced capacitors that run to ground from various places. If it wasn't in the AA165 layout and schematic, I killed it off.

4. I took out the two speakers... one appears to be original orange back Utah, the other was a blue label Fender design, but I"m unsure of either of the years. But, it didn't matter, the speakers SUCKED! I dropped a new set of Emminence Texas Heats. GREAT CHOICE!

5. I turned the balance pot back into the bias pot it was meant to be.

6. I put in a 3 spring reverb tank and new verb cables. (the ebay seller paid for this as the original tank wasn't working)

7. Contact cleaner on some of the pots.

8. I HAD A BLAST DOING THIS! AMP SOUNDS GREAT!

(okay, one more thing... one more mod that Weber recommended to me, more about that later)....

 

[Quencho092]

Re: Fender Pro Reverb is done... for now...

SWEEEET, im not handy enough at the soldering iron to ever hope to do all that stuff, besides the speaker change. Have any clips?

 

[Kent S.]

Re: Fender Pro Reverb is done... for now...

Sounds like you're off to a running start Scott! Really cool guy, post a clip or two when you get a chance. Love to hear it.

 

[Biu]

Re: Fender Pro Reverb is done... for now...

I'll stick to modding guitars, that stuff sounds complicated! :saeek:

 

[Vasshu the humanoid typhoon]

Re: Fender Pro Reverb is done... for now...

Aw that sounds like fun Scott..pictures??

 

[tone4days]

Re: Fender Pro Reverb is done... for now...

sounds great Scott .. glad you had fun ... care to share what the amp cost you, what the mods cost you, and how many hours involved? .. just trying to get a feel for if this is an area of the hobby that i should investigate or stear clear of

cheers
t4d

 

[Lewguitar]

Re: Fender Pro Reverb is done... for now...

Nice. Did you put reverb on both channels yet? I always do. Then I re-voice the normal channel for abnormally great tone: .02 caps instead of .1 and .047 in the tone stack and .02 coupling cap on the output or plate of the 12ax7 instead of .047, 10K or more for the midrange resistor for more mids instead of the original value (6.8K??? I forget.). I also replace the 250 pf disc cap that's the treble cap with a 250 pf silver mica...makes for a little more of a tweed Bassman bubbley effervesent treble tone.

One more thing: you might like to experiment with the negative feedback resistor and double it's value...that'll give you less feedback and a little more growl.

Congrats...this stuff is fun, huh?

Lew

 

[Falstaff]

Re: Fender Pro Reverb is done... for now...

Way to go, Scott. I got mine back recently with the trem lifted (on-off pot installed) and a switch that allows me to turn the negative feedback loop on or off. When off, it really sounds good and gets a bit greasier than stock. I might even ask the tech to find me a happy medium setting and throw in a three way switch instead of the either on or off thing.

How did you make out with that Rumble Mod pedal?

 

[Curly]

Re: Fender Pro Reverb is done... for now...

cool, Scott!

sounds like that might have staved off your building jones for a while

like I said when you got it, the drip edge amps are some of the best deals, cause if they haven't been messed with, then they're pretty much easily blackfaced

and yeah, I'd love to hear clips as well

I really haven't seen a lot of Pro Reverbs, but on paper, they look like such a great gigging amp - 40 watts, 2x12, right? I think that would make a great tandem with that Bad Cat!!!

you've inspired me to take up a couple lingering amp projects - re cap my BF Bassman, and send my 5E3 to Bruce for some troubleshooting.

I kind of agree that the negative feedback circuit is one of the key areas that affects the feel of the amp - to me, that looks like one of the key differences between the BF and tweed amps.

 

[Stratman]

Re: Fender Pro Reverb is done... for now...

Scott:

Have you tried the AB165 verses AA165 circuit?

I find the AB165 to be more stable and tone freindly...

Also, did you add a DWELL to the 3 spring reverb?

 

[mrid]

Re: Fender Pro Reverb is done... for now...

PICS! :dance:

 

[Hot _Grits]

Re: Fender Pro Reverb is done... for now...

Way to go, Scott. I got mine back recently with the trem lifted (on-off pot installed) and a switch that allows me to turn the negative feedback loop on or off. When off, it really sounds good and gets a bit greasier than stock. I might even ask the tech to find me a happy medium setting and throw in a three way switch instead of the either on or off thing.

How did you make out with that Rumble Mod pedal?

I've just had the negative feeback thing done to my '95 custom vibrolux reverb. It sounds great in both settings, and I'm thinking of making it footswitchable, as it would make a great solo boost.

 

[Scott_F]

Re: Fender Pro Reverb is done... for now...

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

Paid 650 for it. Seller paid me $75 back since the reverb wasn't working. I bought all my parts from Kendrick (Gerald Weber). He's a bit higher than other places I could have gotten the stuff, but he doles out a lot of great advice. So, I consider the advice worth the slight upcharge.

I also had to buy a vintage style (yet new) footswitch for the verb and trem. It came with vintage tubes in it. All the preamp tubes are telefunkens and mullards. The power tubes were RCA's and the rectifier was a mullard.

Tubes alone were worth quite a bit even though they were used.

I picked up the speakers from a guy off the gear page for $60 bucks total plus shipping. Not his cup of tea. But definitely mine.

I'm uploading some pics right now.

 

[Scott_F]

Re: Fender Pro Reverb is done... for now...

http://pg.photos.yahoo.com/ph/scott_ms/album?.dir=/c1fe&.src=ph&.tok=ph0MslBBEpZo2GsS

there is a mix of old stuff and new stuff.

the only weird thing you'll really see is where I installed the resistor across teh bias cap. I went with the recommended 15k value from weber. it wasn't enough so, I added another lower rated resistor since I didn't have a 22k one laying around.

I'll try some of the channel 1 mods at some point soon.

 

[Scott_F]

Re: Fender Pro Reverb is done... for now...

Lew and others, look at picture 45. The two small resistors at the top, are those 1/4 watt? I just realized that they are a bit smaller than the 1/2 watt ones used everywhere else. They are what weber gave me. hmm.....

 

[Curly]

Re: Fender Pro Reverb is done... for now...

it's probably just cause they're not carbon

 

[Kent S.]

Re: Fender Pro Reverb is done... for now...

Lew and others, look at picture 45. The two small resistors at the top, are those 1/4 watt? I just realized that they are a bit smaller than the 1/2 watt ones used everywhere else. They are what weber gave me. hmm.....

Can't tell from here so to speak, but I agree with Curly, carbon films or metal films are a bit smaller than carbon composition resistors. I noticed pictrue 50, you got the LED/LDR for the tremolo, if you were a real tremolo hound (which I think you said that you don't even use it), then I'd suggest asking Weber about changing the Tremolo over to the Harmonic Tremolo that Fender first had before the LED/LDR, it creates very subtle changes in the harmonics as well as the volume ... very liquidy. It's a bit diffrent circut than the LED/LDR set up, AND takes up less circuitry to boot. Just an Idea.

 

[Artie]

Re: Fender Pro Reverb is done... for now...

Just to reinforce what Curly and Kent have already said, you can always spot a metal-film resistor by the ends being slightly larger diameter than the body, like the ones in your pic. Those are the little "end-caps" that they connect the leads to. Carbon composition resistors won't have those.

 

[Scott_F]

Re: Fender Pro Reverb is done... for now...

I must have used the wrong resistors. I'm going to go back in and put in the carbon comp versions. I had weber send me all the resistors as well, but I decided to not change them out unless they were crumbling. I'll have to go back and find the others.

The amp sure sounds good, especially when you just hit a power chord or even with a good strong E string. Communication Breakdown sure sounds good on this amp. Those Emi Texas Heats have a nice strong low end to them. No farting out at all.

 

[lastwinj]

Re: Fender Pro Reverb is done... for now...

Just to reinforce what Curly and Kent have already said, you can always spot a metal-film resistor by the ends being slightly larger diameter than the body, like the ones in your pic. Those are the little "end-caps" that they connect the leads to. Carbon composition resistors won't have those.

incorrect. you can have metal or carbon film with the large endbells. and some metal films dont have the large endbells. dale CMF and CCF series come to mind. as do the CPF series, and RW series. corning glass works made some glass encased resistors, too, that dont have any endbells.

the best way to tell carbon and metal fim resistors apart is this: carbon films are usually a light brown color, or deep red for the body. metal films are blue, but they can run the gamut of colors.

then we can add tantalum film resistors, bulk foil, thick films and cernet film.

dale CMF/RN series

germ