Bass response sounds mushy on 1978 Fender SF Deluxe Reverb

[honkytonk66]

Hi everyone,

I picked up a 1978 Fender Deluxe Reverb at an estate auction about 9 months ago and overall the amp sounds really good with the exception that when the bass is turned up past 3, the amp sounds mushy and the bass is not tight at all. Even with the bass turned up, it doesn’t really add any bass.

I haven’t taken the chassis out to look at the inside yet, but thinking it may be due for a cap job. The speaker is original and in good shape so I don’t believe that it is causing this.

Before I start to dig into it, I wanted to see if someone has had a similar experience or any tips to fix this. Thanks!

Don

 

[archetype]

Give it a full service. If it were mine, I wouldn't turn it on again until it was serviced.

 

[corliss1]

^^^Yes, there's really no point evaluating an amp until it's in known-good condition, so it's service time for sure.

 

[Dacious]

Don't turn the bass up past three. The scooped mids of the BF/SF AB763 and later variations of the two channel reverb/tremolo preamp means big bass settings will flub out the output section if you have volume at 5 or higher.

That's common to many of the non-ultralinear amps with tube rectifiers. Very few will withstand high bass settings except at low volumes.

It's also due to the FMV tone stack which is not equal in response between the treble and mid (when present) and bass control.

The BF/SF Bassman, Twin Reverb/Showman and a few others made before the late 70s will give much bigger bottom end.

 

[Dacious]

Oh, and @corliss1 is correct. If it hasn't been turned on in a while new caps and possibly a rebias and general pot lube and jack/ground tighten will give you a good basis to evaluate. The stock speaker is Ok for tone and lower efficiency which is better if you aren't gigging but if you want to preserve it or want more efficiency for gigging then the Eminence GA12 SC64 is a good option.

 

[gridlock]

I would imagine that it needs new filter caps. I would not turn it on until a good tech looks it over.

 

[honkytonk66]

Okay thanks for the input guys. Guess I’ll start making phone calls to find a good tech to service it.

 

[Chiogtr4x]

Okay thanks for the input guys. Guess I’ll start making phone calls to find a good tech to service it.

Where are you in PA?

Are you too far from Jermantown, MD? ( off of 270 which is basically spur off of I-70 S ( 270 is in MD, between 70 at N and 495 DC Beltway at S)

- one of the best Fender amp techs ' in the world' is there ( not kidding he serves a lot of us in Suburban DC, and is awesome)

 

[InstantCoffeeBlue]

Okay thanks for the input guys. Guess I’ll start making phone calls to find a good tech to service it.

Smart move. Wait til it's had a proper service before making any kind of evaluation of the speaker; you may find the stock Utah or Oxford perfectly fine once the amp's been serviced.

 

[honkytonk66]

Where are you in PA?

Are you too far from Jermantown, MD? ( off of 270 which is basically spur off of I-70 S ( 270 is in MD, between 70 at N and 495 DC Beltway at S)

- one of the best Fender amp techs ' in the world' is there ( not kidding he serves a lot of us in Suburban DC, and is awesome)

I’m from Johnstown,PA. Maps is showing a 3.5 to 4 hours, one direction.

 

[Chiogtr4x]

I’m from Johnstown,PA. Maps is showing a 3.5 to 4 hours, one direction.

Yeah, that's kind of far away and PA is big!
( I'm from VA/D.C. but went to College in Erie, PA)

Good luck with DR, i
t is a 'desert island ' amp! ( just sorry I had to sell my '68- we did a ton of Blues, R&R. Country gigs together)

 

[SnidelyWhiplash]

I’m from Johnstown,PA. Maps is showing a 3.5 to 4 hours, one direction.

Could you just possibly ship the chassis??? It would save a lot of time in terms of transit.

 

[FMA]

I’m from Johnstown,PA. Maps is showing a 3.5 to 4 hours, one direction.

I live in southcentral PA and there is a very good amp shop in Lemoyne, just west of Harrisburg called Full Custom Music Repair.

Also, after getting it checked over and serviced, which is a very good idea, think about replacing the stock speaker. I have a 74 SFDR and the stock Oxford didn't cut it, particularly on the bottom end. I replaced it with an Eminence Cannabis Rex, which sounds fantastic in that amp. Very efficient and has a nice bottom and sweet highs.

 

[Chiogtr4x]

I live in southcentral PA and there is a very good amp shop in Lemoyne, just west of Harrisburg called Full Custom Music Repair.

Also, after getting it checked over and serviced, which is a very good idea, think about replacing the stock speaker. I have a 74 SFDR and the stock Oxford didn't cut it, particularly on the bottom end. I replaced it with an Eminence Cannabis Rex, which sounds fantastic in that amp. Very efficient and has a nice bottom and sweet highs.

Agree about speaker swap, but also it's about what sound/ musical 'direction' you want your Deluxe Reverb to go.

It's just the right power output + the 1X12" configuration, to shape sound to more or less breakup, depending upon the music you wanna play...
I owned my '68 DR while playing in 3 groups- Classic Country, a Classic R&R band, and all Blues band.
I guess because I was in a Country band ( and the other bands could be LOUD), it just made sense to me to run amp loud and clean ( no OD pedals in Country band) and use pedals for breakup, with the other bands. All good.

So I had JJ 6V6's installed/biased ( great tech!) and I put in a 120 watt Eminence Red, White, and Blues speaker.
This amp was loud and clear- but not stiff.
I don't think I ever had amp volume past '5' ( not huge gigs, or mic-ed)

 

[honkytonk66]

Yeah Im looking into finding a new speaker right now. Kind of overwhelmed by all the options out there. I mainly play blues and rock. I do like a good clean sound, but also like a little break up at not really loud volumes since I don’t play in a band and mostly at home or my garage.

Id really like to find a speaker that has nice round cleans, sounds good with overdrive, and a dynamic sound. So far I kind of like the WGS g12c/s from what I’ve heard in some videos and from what I’ve been reading. Also a lot of favorable reviews about the Eminence GA-SC64. I don’t necessarily want a bright sounding speaker but want it to still sound like a SFDR. Wish I could try before making a decision.

 

[JDRNoPro]

Best/most important course of action is to get that amp properly serviced. I'd evaluate need for speaker swap after that's done. I really like the Weber 12F150 in my 74 SFDR. The WGS you mentioned would also be one I'd consider. Have an 8" version in my SFVC and like it a lot.

 

[schmee]

Hi everyone,

I picked up a 1978 Fender Deluxe Reverb at an estate auction about 9 months ago and overall the amp sounds really good with the exception that when the bass is turned up past 3, the amp sounds mushy and the bass is not tight at all. Even with the bass turned up, it doesn’t really add any bass.

I haven’t taken the chassis out to look at the inside yet, but thinking it may be due for a cap job. The speaker is original and in good shape so I don’t believe that it is causing this.

Before I start to dig into it, I wanted to see if someone has had a similar experience or any tips to fix this. Thanks!

Don

Deluxe's are not strong on low end. But should be good and loud, and clean with decent bass, on 4 volume and 4 bass. Above 4 on the Bass pot you dont get much more bass response.
Your amp most likely needs filter caps for sure and all other electrolytics replaced.

BUT... the speaker is likely your issue. They were good for lower volumes when new but not so good after decades or higher volumes. They never were good bass response speakers. There are many speakers that will make it sound like a whole new amp with big bass response!
Weber 12F150
Emi GA SC64
Emi Red White and Blues
Weber Silver Bell
etc
Do you have another speaker or cab to try?

 

[honkytonk66]

Best/most important course of action is to get that amp properly serviced. I'd evaluate need for speaker swap after that's done. I really like the Weber 12F150 in my 74 SFDR. The WGS you mentioned would also be one I'd consider. Have an 8" version in my SFVC and like it a lot.

Yeah I’m having the amp serviced now. I have a 8” WGS in my 67 VC and I like it a lot also.

 

[honkytonk66]

Deluxe's are not strong on low end. But should be good and loud, and clean with decent bass, on 4 volume and 4 bass. Above 4 on the Bass pot you dont get much more bass response.
Your amp most likely needs filter caps for sure and all other electrolytics replaced.

BUT... the speaker is likely your issue. They were good for lower volumes when new but not so good after decades or higher volumes. They never were good bass response speakers. There are many speakers that will make it sound like a whole new amp with big bass response!
Weber 12F150
Emi GA SC64
Emi Red White and Blues
Weber Silver Bell
etc
Do you have another speaker or cab to try?

No I do not have another speaker or cabinet at this time. Going to order a new speaker soon. Thanks!