Does anyone use tube shields on EL-84's?

I've been working on this amp and noticed that the EL-84's seem to radiate a LOT more heat than the 12AX7's.

It's seems like the heaters in the EL-84's get very hot compared to the 12AX7's

Before noticing this extra heat, I saw some extra tall tube shields that will fit the EL-84's.

So I ordered some thinking to use them more for tube retention than shielding.

I'm concerned that they may trap the heat and shorten tube life.
Am I way off base here? Will it matter at all?

I know there are wire tube retainers for these tall 9 pin tubes,
but the amp has those bases made for shields just like the 12AX7 tube and I thought to put them to use.

AFAIK this amp never had retainers at all for the EL-84's.

Should I even bother?

Thanks Enzo,
I put the Fluke on range hold and that stopped the blinking and got a reading. 278 ohms end to end.

I did not know that about the inductance current spike thing, so double thanks! 

Also tried the shorted secondary trick and that worked too. 

Here's the thing...
With the meter hooked up if I shake or tap the Tx the reading changes.
Jumps up to something over 300 ohms.

When this was in-circuit and amp warmed up,
if I took a voltage reading from the plate of V3,
at 3/4 volume and up the amp would make weird noises (screeching/whistling) and the voltage dropped on the plate.
Also the slight power Tx hum would go away and got a loud hiss from the speaker.

It does not do this when taking a voltage reading from V4 plate.

This is why I think the O/T Tx is bad.

I have tried different output tubes as well.
The bias needs to be readjusted for the other pair of tubes I have,
but the symptoms remain.

Schem is in post #12.

Edit;
Oh ya, this amp had a fire at one time.
The steel chassis shield plate above V3 is scorched/burnt pretty bad.
The V3 socket was replaced and some of the wiring.
Other wires nearby got kinda toasted too.

Ha ha, stairwell.  :lmao:

Ok, I've been working on this amp for some time now...
Strange problems, weird noises...

And the O/T is gakked.
I just removed it from the chassis and it has some weird resistance readings on the secondary.

C/T to one end reads 165 ohms and 116 ohms the other.
When I measure end to end my Fluke meter goes nuts and the display just flashes O/L. Yes, battery is good.
Tried a different meter (Radio Shack) and it reads 0.270K ohms end to end.  :loco

If I use the Fluke and hook up center tap to either end and shake/bump the Tx the reading changes for a split second.

Ordered a Hammond replacement. 1750S

Non polarized coupling caps should have the outer foil side connected to the low(est) impedance side of the circuit.

Modern caps are not usually marked "foil side".

http://www.aikenamps.com/index.php/where-to-connect-the-outside-foil-on-capacitors

More...

https://hackaday.com/2015/05/20/how-to-tell-if-youre-installing-foil-capacitors-backwards/

1.
The impedance is so close I don't think it would matter which one you use.

2. and 3.
The MOD reverb tanks have solder pads on the connector board that can be bridged with a solder blob, or not,
giving you the option to have both grounded, or none, or one or the other.

MOD reverb tanks at Amplified Parts are reasonably priced and good quality.
I've used a couple of them and have been happy with them.

https://www.amplifiedparts.com/products/reverb_tanks?filters=Brand%3DMOD

Also check Studio Sound Electronics for the "Revisit" brand.

http://www.amprepairparts.com/reverb.htm

These also have the solder pads for grounding options.
I have used these tanks as well and they are very nice.

Yes,
yes,
and yes.

Stairwell?
Is that a song or a band?

What instrument did you play in the band?

Long John Baldry's King of Rock and Roll... man I haven't heard that for ages.
Loved the intro to that song (Conditional Discharge) on the LP.
I think I still have the vinyl around here someplace...

That's cool Enzo. 

I'm assuming you were a cover band playing what we now call "Classic Rock".
Any originals?

Quote from: Enzo on April 12, 2018, 06:13:36 AM
Our band used to play in Ontario a lot, they seemed to like us there.  A gig in Chatham I liked.

Canada had a huge import duty on guitar amps and PAs. like 50%.  SO Canadian bands used Traynor a lot, as it was home grown.  I saw a lot of Traynor over there. I liked Traynor.  Roomy inside, and built like a tank.

Traynor the company was always supportive.  Always ready with schematics or parts.  And I always felt you got a good deal of equipment for your dollar with them.  Can't go wrong with Traynor.  If you will, they were like the Peavey of Canada.

What year(s) were you playing in Ontario?

I've always liked Traynor gear.
They sure seemed to be one of the "good" companies.

Quote from: g1 on April 11, 2018, 08:26:36 PM
Somebody did a nice job on those schematics!
I used to work on a lot of Yorkville stuff so I have a few contacts with the corp.
If you want to post some pics of the guts we can speculate about the parts that look original but don't match the schem.

Thanks g1, but oops, too late...
I decided to strip most of the circuit card and start over.

The mods done were fairly extensive and some original parts moved around to accommodate the mods.

I'll put up some pics when I'm all done with attempting to re-create the circuit/layout.

g1, thanks very much for that.

You got an "in" with Traynor? 
Very cool to know the production date of this amp.
April 70 coincides with the Mallory cap date of Feb 70.

Thanks for the link, I came across that page in my own search.
It helps but some stuff is hard to make out and differs from parts of my circuit that I think are original.
I agree that I probably can't trust a lot of it... but *some* of it really doesn't look touched at all.

The re-issue layout I found too.
It's "close" but differs enough that it's only limited help.

That said, it probably doesn't matter too much,
as there is no way I can ever put this back to exactly like original.

The bright cap and presence cap I knew about from reading other posts here about this amp.
I'll try it both ways and see what I like.

I also found these 2 schematics that are helpful.
Interesting mods...

Quote from: g1 on April 10, 2018, 09:42:45 PM

Quote from: g1 on April 09, 2018, 01:40:39 PM
Some real old ones had 4 digit serial, but they went from 4 digit to 7 digit, so 5 digit is not a valid traynor number.

Except when it is a valid Traynor serial number. 
So the info I had about the earlier than 7 digit numbers is wrong.  I've contacted Yorkville to see if they have any insight about the 5 digit ser.#'s and what the year might be.  Hopefully they will have the definitive info.

You are right about these coming with the Marsland speaker, I think someone swapped it out in this amp.  The original would have had the Traynor part # 7372 on it somewhere.  That 12EAGA8C number seems to be from vintage organs, possibly Wurlitzer.

Thanks g1 

I'm not surprised that the speaker may have been swapped.
I bought this amp a long time ago (mid 1990's) but I recall the guy selling it said it was a Marsland...
... "cuz you can tell by the silver dust cap"...

Of course many speakers came with that feature, so I think he knew the speaker had been swapped,
He made the point that it was "original".
Anyway, no big deal.

Of some slight concern is this amp has had some extensive circuit mods.

Extra preamp tube added, triode/pentode switch, master volume,
Fenderish tone stack with mid control replacing one of the input jacks.
Too bad about the hole in the chassis for the extra tube and the tri/pent switch... oh well...

I am trying to wire it up as per the original schem that is pasted inside on the chassis cover.
Not sure if Traynor updated the schems when there were revisions...
The schem is dated 1969 but some of the original looking part values don't match the schem.
Also kinda tough to find a chassis circuit layout.
Found some pics online but they are not the best quality.

Along the way I will make some "normal" mods as recommended by Kevin O Conner in his book TUT3.
Easily reversible stuff like adding screen resistors and adjustable bias.
I may use the original ground switch to make the neg feedback switchable.
I did that on my 3 Silverface Fender amps, Vibro Champ, Princeton Reverb, and Deluxe Reverb.
I really like the different sound of switching out the neg feedback.

The collectible value of this amp is already compromised but there are lots of them around.
Traynor/Yorkville has reissued the early version and done a really nice job of it.

Edit;
Sorry, this is turning into a discussion about a tube amp... 
Mods, please move to tubes section if you like.

Quote from: Enzo on April 09, 2018, 06:28:29 PM
At least the speaker has a clear 1972 date code.  Eminence.

Traynor was always good sturdy stuff.

Thanks Enzo,

Hmmm, Eminence, and for some reason I always thought it was a Marsland or RSC.
I never looked up the EIA code for Eminence before but there it is... 67

I used to have a mid/late 70's Traynor YGL-3 Mark III Combo 2X12's  "Twin Killer".

Wow that thing was heavy!
Incredibly Loud!
Just all around massive.
Built like a tank.
Good thing it had casters.

Kinda wish I still had it.... but it was waaaay too much amp for what I needed.

I got it cheap ($300.00 CAD) compared to what they want for them now.

It needed a vol pot and one of the output tubes was shorting.
Fixed that and changed the main filter caps.
Sold it for $600.00 a year or 2 after I got it. Oh well...

Even this Guitar Mate is heavier than my 78 Silverface Deluxe Reverb.

Edit;
I found a PDF that decodes the Mallory caps.
They date to Feb 1970,
of course they may have been sitting in a parts bin for some time before being used.

DE = Mallory
B = Feb
0 = Year, in this case probably 1970.

Pics of the original speaker.

I swapped it out for a Celestion G12H 30 watt

I took the vol pot codes cuz some of the other pots are obvious replacements.
The remaining original pots have the numbers obscured by solder.

Here's pics of some of the other hardware/parts.

Serial # pics... the plate looks original and not altered in any way.

Quote from: g1 on April 09, 2018, 01:40:39 PM

...
Some real old ones had 4 digit serial, but they went from 4 digit to 7 digit, so 5 digit is not a valid traynor number.

The P/T sure is massive for a 22 watt amp.

Traynor wasn't shy about using beefy parts.