CHAMP ELECTRONICS -" THE VINTAGE VALVE
AMP HOSPITAL"
NOTTINGHAM, ENGLAND
OVERHAUL OF A VAMPOWER 100 Watt
AMPLIFIER HEAD Mk I
WOW,
I WAS WELL PLEASED TO BE CHOSEN TO DO THIS ONE!
OK, here’s how the story goes. A gentleman named Paul, from
South
Yorkshire here in the UK, rung me to see if I could possibly help him
out with the “getting back to life” of a VamPower
100 watt Head Mk1? Now, I already had a Mk3
on the site but to get the chance at
a Mk1 was
thrilling to say the least! The Mk1 is a very rare amp; about as rare
as “rocking horse dung!” In-fact between us, we
know of only two other MK1s: another in the UK, and one in
Australia owned
by a guy named John Justin, who collects the Vamp products!!
After I had willingly agreed to do the amp for him, Paul came down to
Nottingham to meet me and bring the tired old specimen too. She really
was pretty tired so, after a good chat and a few cups of tea, Paul left
the amp with me and headed for home. It took quite a lot of work and
time to get it back to rights but hey, it was well worth it in the end.
Below is a list of all that ended up being done!!
1.
Straightened rear bent chassis as best
as possible.
2. Replaced broken mains fuse holder for
genuine Bulgin type.
3. Fitted extra metal securing nut to
rear mounted power switch.
4. Replaced broken cord grip in power
plug plus missing screw too.
5. Labelled mains selector switch (be
careful this
doesn’t get moved, it would do a lot of instant damage!!).
6. Repaired “non
working” standby lamp.
7. Sprayed and cleaned all valve bases
and potentiometers (controls).
8. Replaced all four main smoothing
capacitors along
with new mounting brackets (better than the originals now!!). Also used
original hardware on these, as-in the original BA nuts/bolts.
9. Replaced bass channel input jack
sockets (2) and new components with genuine “chrome
nut” type.
10. Removed main power board, changed all
faulty/tired components. Also super-glued all broken corners.
Glue-gunned small bias smoothing caps - nice & solid now.
Sprayed
and cleaned board with special chemicals. Refitted & rewired.
11. Removed main output board, replaced
all resistors
and one capacitor, sprayed and cleaned board with special chemicals
(this board had many duff, tired and wrong components!). Refitted
& rewired.
12. Removed main pre-amp/drive board.
Found a couple
of duff components and changed accordingly. Re-soldered a lot of dry
joints on this board! Sprayed and cleaned board with special
chemicals. Refitted & rewired.
13. All other hardware in the form of
nut’s, bolts washers etc checked for tightness.
14. Replaced all five speaker output jack
sockets
(one broken, one not working so a full new set of matching ones have
been replaced).
15. Found one ECC83 (Mullard) to be
faulty. However,
this turned out to be the wrong valve anyway! This has been replaced
with the correct valve….ECC81, also Mullard.
16. Supplied full quad set of
used-but-very-good Mullard EL34’s (2 matched pairs).
17. Full bias set-up and bench test.
18. All other wiring tidied up and
cable-tied where need be.
19. Supplied/fitted missing 2BA cage
mounting nut.
20. Supplied four new brass 2BA screws
and four new cabinet feet.
So now, having finished all the above, it was time for Paul to collect
his baby and let me know the results. On the test gear it was superb,
and I could see that it was going to sound great! This amp has a
control on
the second channel called “a bite control”. This is
a type
of overdrive and is designed around the idea of the early fuzz boxes,
only using a tube (valve) to achieve the desired results rather than a
transistor. To the best of my knowledge, this is the only amp of its
kind to have this method/design of circuitry, and it was “way
ahead
of it’s time” too!
You may well be wondering why I’m making such a
“fuss and
interest” on this particular amp? Well for those of you who
don’t already know this:-
The VamPower 100 watt
head Mk1 was the
late Marc Bolan’s choice of amp both on stage and in the
studio.
Bolan had a short period between 1971-4, where his guitar tone was
awesome. How or why he came to use VamPower amps is not known; maybe
sponsorship (?). No one else of any note was using them at that time.
It is known that he loved the “Bite” control.
During the
era circa 1971-2 he used this amp extensively, and great examples can
be heard on “The Slider” album, with the track of
the same
name being a fantastic example of this sound with its “woody
growl”. It is believed, through general photos available on
the
net, that he used to drive the Vamp with a HH 100 watt transistor head
and also, along with both the amps, he used a “Dallas-Arbiter
Rangemaster treble booster” with a Germanium transistor in
it.
(These are fetching really silly money nowadays!). It was the
combination of these amps, the Rangemaster, and his 50’s Les
Paul
with its randomly wound Humbuckers and Bumlebee capacitors that gave
Marc his unique sound…..the sound that Paul, the amps new
owner,
was seriously looking for!
So, after now having had the amp back for a few days I got the call
from Paul………….. "Yes" he
said….."that’s the sound!!!"
Now, here’s where the story takes a possible unexpected
twist!
Paul had bought the VamPower head from an Australian collector of Vamp
products named John Justin, whom I mentioned previously, although it
had
actually been stored in a London recording studio where it had
apparently stood in a corner, untouched for many, many years. However
the mind boggles….. As Marc did most of his recording
in
London studios, could this have been Marc’s actual amp from
back
there in the seventies?……Who knows? Another thing
that
makes me wonder about this is the fact that this amp has an unmarked
slave in/out socket on the back panel, yet it did look factory fitted,
whereas the photo of the other one in Australia doesn’t have
this
socket. Maybe Marc had this factory fitted for the use of
linking in/out his HH head? If any more information on this surfaces I
will post it herewith.
The amp is presently being recovered back to original by a great guy
for doing this……James Payze (Click HERE
for James' Website). When it has been finished, Paul is going to send
me some photos
and I will be posting them herewith.
I have made some useful comments on the photos' captions. I
really enjoyed doing this one. Thanks for your interest in the site.
Cheers, John.
Finished
& ready to “Rock ‘n’ Roll!!
As received.
Note the two “non original” black nylon jack
sockets on Channel 2.
As
above, no output tubes & smashed fuse holder.
The
output board…….Cooked, charred, burnt, many duff
components, dreadful soldering & incorrectly replaced/bodged
components too!
The
pre-amp/drive board……not as bad as the output
board but still needing attention!
The
“non-labelled” slave in/out socket which certainly
looks
factory fitted. It is the same branded jack socket as all the others
& is wired with the identical type shielded cable as-is used
throughout the rest of the amp!
The output
board removed.
The rebuilt
output board.
All
re-soldered & chemically “cleaned-up”
underside of the output board.
The output
board back in place.
The
power supply board, all the resistors were well tired or duff! Also,
note the broken corners where the mounting bolts locate. These circuit
boards were so bad all those years ago. They are made of a very brittle
& cheap type of bakelite, which one only needs to look
at them
& they break! These were already broken on removal of the
various
boards/panels.
Underside of
the power board, all re-soldered & chemically cleaned too.
The
power board back in place with all new resistors. I have also
super-glued all the broken circuit board corners & glue-gunned
all
the wire-ended capacitors - the trendy, sensible, & good way to
secure them nowadays!!
The
four new smoothing capacitors in place; better than the originals!
Tightening up the HT supply on any tube amplifier improves the
“bottom-end” & “kick”
without effecting
tonal quality.
The
voltage selector switch - this is not a good design/idea!! It can
easily be “knocked” and if
so……..would cause
a possible/immediate amount of damage! I had advised Paul (the amps
owner) to be very aware of this, although once in its case &
with
the back grill in place it is very unlikely that this would actually
happen. Nevertheless, still worth noting!
The
incorrect black jack sockets that had at some point been replaced have
now been changed for the correct “chrome-nut” type.
Plus a
“close-up” of just two of the four new, main
smoothing caps.
Underside of
pre-amp/drive board; prior to any commencement of work.
After all
work & chemically treated.
One
of the output jack sockets was smashed, and another wasn’t
working. As I didn’t have the same brand, it made better
sense to
simply change all five to a different brand…….but
still
of the chrome nut type, as the originals.
Both pre-amp
& output boards back in place.
I
just love this last photo! What you are looking at is the
“above
chassis heater fuses”. I am not aware of any other amplifier
manufacturer way back there in the seventies that actually fused their
tube (valve) heater supply. The ironic thing is that nowadays this is a
compulsory/law issue and all amps have to have this! It is now done
however by using standard fuses rather than two pieces of fuse-wire
across tags, but hey…..the Vamp products were all
“well
before their time! Another point worth mentioning here is the
fact that not only does this amp have the “heater
fuses”, a
“bite” (fuzz) control, but also it has four
individual bias
controls (one for each output tube) plus the facility to check each
tubes’ bias via the four additional, individual cathode
“bias check” resistors! This amp (and in-fact all
the Vamp
products) was “way ahead of its time! 101% bravo for this!
PHOTOS OF THE AMP AFTER RESTORATION WORK CARRIED OUT BY JAMES PAYZE:
(To visit James' website, click HERE.)
Front & back of the amp as she is now.
Paul's complete set-up, all recovering compliments of James Payze.
I
have just (February 2008) been contacted by Dave Roffey who was the
actual person who designed the Vamp amps in the 1970's. With his
permission, I have added his email below because it offers a
fascinating insight into the history of these great amps, and the Marc
Bolan connection:
"Hi John,
As the ‘old timer’ who
designed the Vamp amp, seeing your restoration has just given me a warm smile
and good memories, (those that are still available to my brain!).
That
amp was made at Triumph Electronics in Purley, where I first started work in
music electronics. Triumph made stuff for VOX and their own Tranny amps as well
as valve stuff. Made by a guy called Roy I believe, ex drummer of the then Ram
Jam Band. Great guy, and excellent wirer. (judged by the artwork
doodle).
The ‘bite’ control brings back memories of the rows I had with
the purists. Being in a rock band at the time, the overload control was a
definite requirement for me, but it took the wisdom of the MD, Geoff Johnson, to
see it should go on.
Marc Bolan frequented a music shop in Lewisham,
South Eastern Entertainment. This was run by Frank Taylor, who approached
Triumph to make the Vamp amp for him. Frank Taylor then went on to manufacture
the amp himself, along with me as the designer. I left after a while, leaving
the music side of the industry.
Anyway, thanks for the
memories,
Dave Roffey"
