Deep Lush | '64 Fender Reverb Unit Pt 2

[@Tonetwisters]

I am blessed to own a '63. It's at the tech's right now ... Hope to have it back tomorrow, Saturday and hope that the new capacitor he installed makes it sound the way it should. My older brother bought one brand new, when they first came out. Thanks for the primer on this guy ... they beat the sparks out of the on-board reverb units. Back in the VERY early '60s, I was a kid who loved to play his Jazzmaster through his reverb unit and his PRO amp ... I was king of "Ghost Riders In The Sky."

[@PeterMoore350]

Noice. I haven’t tried any of them. What modern Fender or other valve/tube amp equivalent would you recommend? Cheers from NZ 😎🎸🤘

[@PeterMoore350]

Oh I’ve got a couple of amps. Hughes and Kettner Grand Meister Deluxe 40 and a very reliable 2017 Bugera T50 infinium which despite a lot of poor reviews is actually quite spectacular and super reliable. I bought it NOS in 2022 so it was 5 years old before I even owned it !! I can give you tips on that amp. Main tip is switch the tone cut off so basically all the way to the left. There’s pop when switching between clean and dirty channels but just stay on clean and use a TS for overdrive. Problem solved. Probably gonna buy another one as a backup given the reliability. The GMD40 is awesome but it’s got a lot of bells whistles and a bit of a learning curve. Stock valves are Chinese. Mine failed. Valves only had 6 month warranty. Amp has 3 warranty. I’ve replaced those EL84s from JJs Slovakian made. Amp is super quiet now.

[@FrankDux-rq7go]

I love the orange glow of that tube.

[@YeatzeeGuitar]

For the owner, a buffered pedal inbetween the spring tank and your amp brings the tone back to life. A boss tuner I bet would work fine, or really any boss pedal on a battery would be viable if you don't want to deal with extra wires. You can, of course, also use the courtesy outlet on the back of the amps to have a little onespot 9v power supply and just keep it in the back. Lots of options!

[@randyrich2039]

If you're working on one of these, the old ones, you should take it apart and remove the Gibbs tank (spring unit) and check the condition of the foam spring dampener that's glued to the inside of the face. The original foam is that old yellow stuff that rots away easily. Pieces of it can get in the springs and be a problem, even keeping the springs from working, meaning no reverb. Scrape it out and replace it with some new gray foam, easy to do. No more potential problems.

[@EricClapton1945]

All this stuff goes right over my head but it's really interesting!

[@Tibbon]

I'm doing my first recap of a 66/67 Bandmaster right now, and your videos have been invaluable. I'm taking it slow and doing it right. Today, a new 3 prong power cable!

[@Satchmoeddie]

Guitar & bass amps that technically did use transmitting tubes: The famous Chet Atkins Standel Model 15L25 used 807 (famous WWII) transmitting tubes back in 1953, and the early 360 Watt Ampeg SVTs used 6146B/8298A tubes, also transmitting tubes, but no need to use alcohol wipes or white cotton gloves when handing any of those tubes. The 807 tubes were everywhere for cheap prices in war surplus sales after WWII. By 1968 Ampeg was just being weird. Telefunken actually developed a super power audio tube inspired by the Ampeg SVT but it was only produced long enough to make a few hundreds of engineering samples. A few amps were made to use that tube. 150 watts from one pair!! Wow!

[@Satchmoeddie]

Yes, definitely the exception, not the rule, and the 807 is really only a beefed up 6L6WGB or 5881 with a plate cap, so a 6L6GC can be substituted for any 807, after rewiring the sockets and removing the plate cap wires. The 6146B is in it's own family of transmitting tubes and there are no audio tube analogs to those. Weirdness on Ampeg's part.

[@sgt.grinch3299]

Thank you Lyle.

[@tomk1tl39]

Your explanation about the gnd etc, made me understand why my " homebrew 6G15" about the small amount of noise I have. . . using it with a Fender 5F2A scratch unit I built . . . still sounds good 😎

[@scottwilcox6313]

Wow, what a nice amp. It's just a nice piece of history. Great work as usual.

[@YeatzeeGuitar]

Happen to own both a 90's reissue and a '64, and both sound great. Honestly, I'd recommend the reissue every time if you can get an early one with the better tank since the ground loop issue isn't a thing. They sound slightly different, but I've also compared my vintage tank to another vintage tank and they sounded just as different.. but again all sounded good! I've also experimented with tubes, and to my ears at least the 6k6 vs 6v6 is just changing where the knobs end up to get the same sound.

[@jutukka]

Sometimes those circuits can go into parasitic oscillations because there is no grid stoppers. So if there is some strange extra noises, some of them can be caused by those oscillations.

[@shakeypeet]

Cheers , and a big thank you for ALL that you do .

[@jhjanko1]

I built one of these to go along with a 6G7-A Bandmaster. It’s my opinion that the Brownface amps were the best. Or just the most “cool”. Anyway, I love your channel and look forward to new content. Thanks for the efforts.

[@velutumbra]

I am wondering when did grounded AC plugs started being a thing/mandatory in the US?

[@BenState]

1992, NEMA 5-20

[@randyrich2039]

I have a 1963 6G15 (reverb unit) that I've used on and off since I bought it in 1970. So I've never owned a reissue, but I've heard it said, from several sources, that if you change the 6V6 in the reissue to a 6K6 it will sound "more like it". I don't think it'll hurt anything since the circuit is the same. I haven't heard anyone saying "don't do that, it'll ruin the unit", but check into it first just in case. They don't make reissue 6K6 tubes so you'll have to find an NOS from a vintage tube dealer. RCA or Tung-Sol are available for not much more than reissue tubes cost.

[@PsionicAudio]

Yeah, the RI circuit is the same except for two added resistors that are improvements. 6K6 drops right in.

[@ex-subsailor3480]

Thanks for your videos PA. I would really like to get your take on the new Gibson Falcon 5 and 20 amps with respects to the build quality. I have seen videos discussing the sound but not so much on the build quality. I trust your opinion but most of the videos I have seen are from dealers. And as dealers, they may be biased or afraid to piss off Fender with a bad review. Thanks again PA!

[@ditchgator1]

😎👍👍

[@TheArtofBlues]

Hi i have the brownface version from ‘61 that needs work. How can i send to you? Whats the contact info? Thanks in advance

[@omarmolina207]

Adding a big 0.047 - to 0.1μF film cap in series after the input jack out of the question? Should be relatively transparent and lots of guitar pedals use them to keep DC off the input. Some do voicing with smaller values, but we don't want that here.

[@PsionicAudio]

It already has one. And it tests good.

[@omarmolina207]

I see that now. Pulled the schematic after my comment. In that case about the only other thing it could be is DC on the 12AT7 grid from somewhere. Maybe disconnect the grid to see if it still does it just going through the cathode follower. Otherwise I'm at a loss as well.

[@PsionicAudio]

Pulled the AT, still there. Has to be the AX grid, might add a grid stopper. Trying not to change the old circuit.

[@PsionicAudio]

It’s an odd circuit.

[@omarmolina207]

One more thought. I did once have a gooped guitar pedal with DC on the input. I ended up having to put a large 0.22μF cap immediately at the PCB input lug on the switch itself. You end up with series capacitance, so big was the only way to go. If you added a 2nd cap at the jack itself before the split as a proof of concept, does that get you anywhere? If so, then maybe finding an elegant way to insert the cap before that first eyelet might be worthwhile.

[@randyrich2039]

ALERT! Someone below said that you could put a pedal between the reverb unit and the amp. I tried that some years ago with an overdrive and it blew the op amp in the pedal the second I switched it on. Some types of pedals might work but I'd be cautious about trying that. I replaced the op amp and all is well, but I won't try that again.

[@PsionicAudio]

The output is about the same level as a guitar. Nominally unity gain. So something was very wrong in your setup. Should not be an issue, though overdrive after reverb would not be a very useful order.

[@randyrich2039]

@@PsionicAudio It wasn't my set up. It was an experiment. I overdrive the amp anyway, which is overdrive after the reverb,, so I wondered how it would sound with some extra overdrive after the reverb (instead of moding the amp). I didn't think it would be a problem either. It was just a cable from the reverb to the pedal, from the pedal to the amp. I hit the switch and POP! went the op amp. The pedal is a Kingtone Duelest. I replaced the op amp (on the side of the pedal I tried) and it's fine. This was about 3 years ago. The pedal is still good. I don't use the reverb like Dick Dale, check out Kid Ramos or Hollywood Fats KZbins, you'll see what I mean. It's a sound a lot of us west coast blues guys have been into since the early 70's. Kid uses his into an AC30 cranked up to a very nice overdrive (I think you'll dig it), Fats (RIP) used 50's Fender amps and a Space echo. Anyway I was just giving a heads up because of my experience doing that. Thank you for the reply and your great videos, you've really helped out an old B Flat who's struggling along on social security to get his old Fender amps working right for once. The techs I had used over the years (I've made a living playing music since '69, no day jobs ever), really slopped the job, your methods are what I consider "the right way". Your videos helped me restore my '58 bassman, '56 deluxe, '63 super reverb, '63 reverb unit, and '64 deluxe reverb. I carefully did what you showed us and they're all sounding great now. Thank you again. In my opinion you're the King of amp techs.

[@PsionicAudio]

That is very nice of you to say, and even better to know I’ve been able to help. I just can’t imagine this circuit doing anything that would damage an opamp. I mean, yeah, a cap could leak DC but I would expect Kingsley to have input caps for protection against such things.

[@PsionicAudio]

Btw I’m not arguing with you - I believe you. It would just be a very strange and rare occurrence.

[@randyrich2039]

@@PsionicAudio Yep I'm a fan of yours. If I could've afforded it I' would have just sent my gear to you with a blank check. But, I also wanted to do it myself, to see if I could, and I'm bored out here in Taos, NM. I don't want to hang out a shingle, just maintain my own stuff and maybe help out a friend. That's how I found your site. I took electronics in high school, (mid 60's), built a radio and a few projects but since then the only time I used a soldering iron was to replace a speaker or a bad pot. So, this has been great, thanks again. BTW, I just last week installed the Lar-Mar type 2 in 3 of my amps. Doing it the same way you did. They work great. There were type 2 master volumes in the amps that were done in the late 70's early 80's but not exactly the same and kind of hokey, they worked okay but when I looked at the job I knew they had to be removed. So I took them out when I did the restoration, and tried the type 3, the easy one, but I agree with you, those don't really cut it. Also I might be able to be a little help to you, I discovered something when I was working of the '63 Super Reverb that could be helpful for you. Let me know and I'll describe it the best I can. It slipped by several amp techs over the years, and the answer I always got to my ? was "some of these are just that way, not much you do". But actually I fixed it. Thanks again sorry for the mini novel, I know you're a busy guy. 😸✌

[@danielmargolis3210]

Isolation transformer in a box? Who makes one?

[@BenState]

many companies, google is your friend

[@matthewf1979]

I can't recommend the Radial Twin City enough if you need a ground lift/phase switcher/amp switcher. I haven't had a problem with DC on the input or the high frequency attenuation in the units I owned in the past. Then again, it was ~6 years ago when I sold the last one, so I might be forgetting something.

[@PsionicAudio]

The HF attenuation is caused by the Tone circuit as it affects both wet and dry, but affects dry more when wet is grounded out with the footswitch. Not much real separation there.