"Customer brought in a 'Volu-Tone' amp from 'The Volu-Tone Co', Los
Angeles CA serial #5501 couple of weeks ago and I thought I'd share a
bit of the experience with the group...

This thing was *really* in a closet for over 40 years- cloth covered wire all intact, case good (except the leather handle had rotted), a beauty to behold. The 'new' owner got it at an estate sale in KC for $30 (where the hell was I?) and immediately brought it to me. Before even
plugging it in, a quick check of the power supply caps; the paper boxed power supply caps had leaked major, and one was a dead bolt short (a major argument for using *at a minimum* a 'variac' and AC current meter when bring up one of these 'finds'; can prevent *real* additional
damage!) Both (only two in it!) coupling caps were resistive, and the outputs'
cathode bias resistor had corroded open; new 3 prong AC cord and a little cleaning...

Built 'sometime' evidently in the 30's, 5Z3 rectifier, 2)42 outputs, 2)6A6 preamp tubes in their own little box (all tubes turned out to be in good shape); field coil (10") speaker of course.

And now the really neat part: this is a *fully balanced design*, with a
proprietary *hum-bucking pickup*(!) Maybe I shouldn't be surprised, the
'ol timers around here will probably say 'everyone had one back then'
;-)

Check out US patent # 2026841 by the designer (and evident builder) of
this piece: Mr. Arnold Lesti dated Jan 7, 1936. It shows the deadly
'mystery switch' this amp has, which, as received, *would momentarily
send 400 volts DC up the guitar cord(!) *as designed*.

Repeating what Mr. Chidlaw had guessed (correctly!) the special pickup
included was designed to *magnetize the guitar strings* for operation
(no magnets in the pup.)

One wire disconnected soon defeated what would no doubt be a real *eye
opener* to someone operating this amp with 'regular' guitars and
cables...

Listening tests? Rocks! And I mean ROCKS! I left the circuit completely
as designed (except for the momentary 'death switch') and there's
nothing there to 'muddle' yer signal- the first stage triodes' grids
connect directly to the 1/4" phone TRS jacks (I know, a tube shorted
plate to grid would spell disaster; 'informed customer' operating here.
It'll probably see a series input cap/DC return resistor mod soon.); one
coupling cap (per 'phase'), no tone control or feedback. The common
cathodes' resistor (250 ohms) for the two #42 output tubes (at measured
plate voltage) works out to make about 15 watts plate disp. per bottle;
according to my GE specs, they're only supposed to see about 11 watts
each. I'm going to assume for now the original designer(s) 'knew what
they were doing', and leave it as is- it sounds so good! AC line power
current meter barely twitches when you max it out- 'Class A', anyone?

The drive transformer for the output stage lets me 'un-balanced drive'
this amp; plug a regular guitar right in and go (using 'one side' of the
fully balanced preamp circuit)... but if you want this thing to *really*
go, hook up a 1:1 transformer on the input in series, with the secondary
center tapped referenced to ground (that's 3db more preamp gain, right?)

If anyone would like to know more about this particular piece, just let
me know; I don't know if I'll get time to photo and post pics (before
customer picks it up), but I did hand draw a partial schematic (which
looks more like a block diagram- maybe 20 parts in the whole thing?) Or
if anyone can help accurately date it, please let *me* know! (What look
like potential date codes on the transformers put it to build in 1929;
predating the patent.)

Cheers,
-Robert

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[This message was edited by Andy Volk on 01 January 2003 at 10:28 AM.]

Volu-Tone is in business today, a literal descendant of Schireson Brothers, distributor/manufacturer/retailer, who made Volu-Tone originally. (Best known for getting its reso-manufacturing socks successfully sued off by National-Dobro for patent infringement.) It's an electronics distributor in Simi Valley (they're in the book (a/c 805)), run by Gary Schireson--third or fourth generation member of the Schireson family.

When I came sniffing around about Schireson instruments in the early-mid-90s, Gary had almost no knowledge of the family company musical-instrument legacy. (He's since become an avid collector of Schireson instruments and items.) The Schireson family sold the longtime retail store (a few years before I happened onto the building in the early '90s) in downtown LA to employees, who've re-christened it the International House of Music. However, there are still "Schireson Bros." signs painted on the brick sides of the building...unless that's gone away since I stopped working up Broadway at the L.A Times in '98.

[This message was edited by Ben Elder on 14 June 2006 at 07:42 PM.]