No output from 1964 Deluxe Reverb - Help!

[J M Fahey]

Just curious, where in Africa are you?

As said above, Radios and TVs are universal, and everywhere there is a Tech for them, at least in the larger cities.

Probably not trained in Tubes but he will know what is meant by "measure voltage on pin 8 of V3" and similar instructions.

And you might be surprised, an old Tech might have worked on Black and White Tube TVs or tube PA equiment from, say, a Church within his professional life and still remember some skills.

I bet Enzo can guide anybody on Flipper and similar machines repair, even if not seen them for many years.

EDIT: just checked Yamaha authorized Service Stations in Africa.
I see very well equipped shops in:

Algeria
Angola
Burundi
Cote D'ivoire
D.R.Congo (East)
Egypt
Ethiopia
Gabon
Ghana
Kenya
Madagascar
Mauritius
Morocco
Mozambique
Nigeria
Reunion Island
Rwanda
Senegal
Seychelles
South Africa
Sudan
Tanzania
Tunisia
Uganda
Libya
Zambia
a tech there will not know much, if at all, about tubes, but by necessity they are well trained and equipped to deal with SS amplifiers, mixers, keyboards, PA equipment, etc.

[J M Fahey]

Is this the amp?

I guess you are in Angola ... and not exactly in a hut in the middle of the jungle but in a large, modern city.

Or the amp now is in Tanzania ?
Same thing.

*Somebody* services the Marshall / Hartke / G&K / JBL powered monitor / keyboards / Recording Studio which are seen in the Videos.

FWIW I used to run the Brazilian based "Amplificadores Valvulados" page in ORKUT and we had some Angolan Members.
In fact, my co-administrator regularly travelled to Angola for Business reasons, so often that we all joked about his "other" big booty African wife(s) which he hotly denied having

[Leo_Gnardo]

it may be worth opening and checking for obvious loose wires...

Gets my vote. Look for the obvious first.

Also, would be good to look at all tubes when amp is on, make sure all filaments are lit. The small preamp tubes have two small filaments each, look closely and you'll see them. No need to remove the amp from its box to do this, but it is a good idea to remove the upper back panel to see the tubes better. And even easier to see the dimly glowing orange filaments if you do this check in a darkened room.

It's been mentioned that an amp of this age should have some thorough maintenance to make sure it keeps working, and I agree 100%. But first, let's find the problem and solve it. If you can mail order parts, and you have some basic tools, you can follow up the repair with maintenance as your schedule allows.

These amps are valued highly even in densely populated areas. It must be a very special treasure to have one way out there where you are. Let's keep it going.

[52 Bill]

And before you even open up the amp, turn down the reverb and give the top of the cabinet a good Enzo whack to see if the physical stimulation will cause any response.

[bob p]

Hi all, played a gig w my Deluxe Reverb (1964). Brought the amp back home where it sat for about a month. Tryed playing it yesterday and almost no volume comes out it. If i crank up volume knob guitar can be heard low and distorted. Issue happening in both channels. Changed all tubes, issue persists. Tried external speaker, same issue. Reverb and tremolo can be heard /seen to be working.

This wouldn't be the first case where an old amp got run hard and performed well, but the next time it got turned on it had low volume and distorted. Old worn-out cathode bypass caps are famous for causing this sort "worked great yesterday but totally dead today" failure mode. Sometimes a good stress test is all that it takes to get them to declare themselves.

[Josephcarassojunior]

Many thanks for all the replies. For some reason i stopped getting email notifications so didnt know i had replies.... So here is a brief update. I have opened the amp. I am still alive, no shocks . But couldnt find anything obviously loose or disconnected. Yes the amp stays in Tanzania and so do I. Yes that was me in the video but using a super amp, not the deluxe, which is sitting beside it. Embarassing! Yes, the amp is a small treasure to me. Really appreciate all the answers, thoughts and warnings. I will try to open and check it again. I do have a multimeter, can and have done solders (in guitars) and can order parts from here, so any thoughts on basic tests i could do to try and identfy the problem would be appreciated. Leo_Gnardo, would you have a picture of that part that usually comes loose? Wanted to be sure how it looks like before i open it again.

Txs again for all the inputs and time, all very much appreciated!

[Josephcarassojunior]

I have a short video of how the volume coming out of the amp at 3 and at 7/8, how it sounds. Perhaps it would help w the diagnosis... How do i post it here?

[pdf64]

It's probably best just to upload to youtube and provide us a link; set the video's privacy to 'unlisted' if you like, then only those with the link can access it.

If you are competent to work inside a live amp chassis (? - there's no shame in admitting not), I think that the most useful thing you could do now is to undertake a voltage survey of all the tube socket terminals; Vac for heaters and rectifier input, Vdc for all others.
See how that info can recorded / presented http://bmamps.com/Schematics/marshal...ll_jtm45tr.gif

Keep the meter and its leads well away from any circuitry.
Turn all controls to minimum.
Ensure that there's a load on the main speaker output jack.
Keep one hand behind your back (unless that's impossible).
Sharpen the meter probe tips to avoid them slipping off the terminal under test, and possibly shorting things out.

[Josephcarassojunior]

Here is the link to the video where i play the amp, volume 4 and 8. Guitar is a jackson soloist, hot output. I recall it used to drive the amp into a sweet overdrive at 4...

https://youtu.be/16rAam2Ap5Y

[pdf64]

Is everything on the OT secondary circuit good, eg speaker, cable/jack plug, back panel jack socket?
eg
unplug the speaker jack and measure resistance across it, eg ~7 ohms.
de-energise the amp, plug a good cable into the main speaker jack socket, and measure resistance across the other cable jack, eg ~1 ohm.

[Chuck H]

Sharpen the meter probe tips to avoid them slipping off the terminal under test, and possibly shorting things out.

Maybe I just didn't know about this or consider it on my own, but that's really smart. Even if I HAD thought of it I probably wouldn't have tried because I don't know that meter probes aren't plated.?. But if you've done this without damage to probes, I'm all over it.

[pdf64]

My thinking is that the probes are a consumable, as the leads will fail eventually anyway; so balance that against the sh1t that can happen if the probe slips (especially if pressing on hard to break through surface gunk/oxide/flux residue on the terminal), and my verdict is to keep them sharp.

I've not noticed that sharpened probe tips develop oxidation etc probs, or are otherwise less long lived than in my pre-sharpening days, but if you're near the sea or other more corrosive environment, YMMV.

I got the idea to sharpen tips from some forum thread, can't remember which or who (thanks if the originator is reading this!).

SGM passed on a useful idea, to slip some sleeving / tape over any unnecessarily shaft of the probe tips; I've tried that and thought it beneficial, but occasionally the sleeving needs to be removed, eg for 2mm test point sockets, and indolence delays me getting around to replacing it.

[bob p]

SGM passed on a useful idea, to slip some sleeving / tape over any unnecessarily shaft of the probe tips; I've tried that and thought it beneficial, but occasionally the sleeving needs to be removed, eg for 2mm test point sockets, and indolence delays me getting around to replacing it.

Heaven forbid that we should actually give SGM props for telling us something useful.

When I don't have a non-metallic screwdriver handy, I've done the trick of putting HST over a regular screwdriver to insulate it.

Like everyone else, I've had probes slip off of their targets to land in an unwanted location. Sometimes that produces a spark. When I get into really tight spots, I like to use a Pomona probe that has "mini grabber" clips at the red and black ends. Sometimes this requires switching the amp on and off when I'm working in a really tight space, but this method absolutely precludes the problem of pointed probe slippage.

[Leo_Gnardo]

SGM passed on a useful idea, to slip some sleeving / tape over any unnecessarily shaft of the probe tips

Heaven forbid that we should actually give SGM props for telling us something useful.

Heck I've been putting heat shrink on probe tips for a long time. Since before SGM was advising his mom how to change his diaper...

Very handy if you're going to use shunt method for measuring bias current. If you have an accident then only yourself to blame.

Yes, definitely file sharp points on meter probes. If they're sharp enough you can jab them through wire insulation. I find it a genuine PIA to have to mash a probe onto a terminal or component lead.

[J M Fahey]

@ joseph carasso: to be certain we all talk about the same, please confirm whether this layout does or does not match your amplifier.
from: 1963-1967 "Black Face" Deluxe Reverb



you might have this slightly different version:


You will have to pull the chassis out of the cabinet, put it on a table using either a couple thick books under the transformers or a *chassis cradle* (which you can improvise easily because you do not need it to be adjustable) , so tubes do not touch the table surface at all:


mine is a fixed simple U shaped thing made out of chipboard , glue, and a couple nails, just build one for your particular amp and that´s it.

Then make a 2 or 3 meter cable so the chassis can be plugged into the speaker, remember to use the main speaker out, not the extension out.

You DO need a plug into it to open the output shorting jack.

after you confirm which one you have and have the chassis safely upside down onn a table, with good illumunation and space for your tools, we can suggest some checks and measurements.

Só por curiosidade: o senhor é Brasileiro?
Pegou o ampli no Brasil ou comprou nos USA?
Usa ele hoje com transformador 220/110?
Obrigado.