Watkins Westminster valve amp - UK Vintage Radio Repair and Restoration Discussion Forum

recordplayer · 12th Aug 2018, 1:50 pm

Hi, I am repairing a Watkins amp - even though it works I am going to change all the Hunts caps, and the electrolytics, and any resistors that are out of tolerance. I think it dates back to about 1956 and the valve line up is: 2x ECC83, 1X 6AQ5, 2XEF86, 1XEL90, 1X EZ80 which I will also check out. Does anyone have the schematic / circuit diagram or know the exact model - see pics.

ms660 · 12th Aug 2018, 2:58 pm

I can't find anything about that chassis that's shown for the Westminster, but I'm no expert.

Lawrence.

Edward Huggins · 12th Aug 2018, 3:18 pm

That's a lot of valves for a single ended EL90 amp. Maybe they are used for effects or the OP has the line up wrong?

TonyDuell · 12th Aug 2018, 3:29 pm

I think a 6AQ5 is an equivalent to the EL90. Which, given one of each in the lineup, suggests it could be a push-pull output stage using those 2 valves

Alistair D · 12th Aug 2018, 3:44 pm

Not found a schematic but this page gives more details about the Westminster models.

http://www.vintagehofner.co.uk/brita...stminster.html

Al

ms660 · 12th Aug 2018, 3:51 pm

The output transformer looks like a Radiospares Hygrade…?

Lawrence.

buggies · 12th Aug 2018, 7:23 pm

Again no schematic but the third picture in post #1 looks identical to this one on the site mentioned by Alistair D

http://www.vintagehofner.co.uk/brita...er/west21.html
c1956 WATKINS WESTMINSTER AMPLIFIER COURTESY OF MICHAEL KERR, ESSEX, ENGLAND:

and the internals:-
http://www.vintagehofner.co.uk/brita...er/west19.html

recordplayer · 12th Aug 2018, 7:23 pm

Edward , with all due respect the valve line up is correct - when I said I would check the valves I meant the condition of the valves not the line up . Yes there are a few valves but they are the right ones - if you read my post it says the amp is working - so they can't be the wrong valves !

mole42uk · 12th Aug 2018, 7:35 pm

Quote:

Originally Posted by ms660

The output transformer looks like a Radiospares Hygrade…?

Many of the early Watkins amplifiers used RadioSpares transformers.

ms660 · 12th Aug 2018, 7:45 pm

Cheers, it was the colour on the label that made me think it might be RadioSpares, followed by the 6 tags on one side.

Lawrence.

recordplayer · 12th Aug 2018, 8:00 pm

Hi , yes I checked vintage Horner , I guess the 1956 one is the closest to mine - will work off that schematic - very similar to mine

Edward Huggins · 12th Aug 2018, 8:54 pm

Quote:

Originally Posted by TonyDuell

I think a 6AQ5 is an equivalent to the EL90. Which, given one of each in the lineup, suggests it could be a push-pull output stage using those 2 valves

Arghhh - I missed this. You're right. No matched pair here then. I guess it will sound similar to 2 x 6V6s in PP. Not many early UK Guitar amps used these.

Valvepower · 12th Aug 2018, 9:25 pm

Hi,

According to the r-type valve site the EL90 design is the classic 6V6 squeezed into the tiny B7G envelope!

Maybe they were trying to get near the Fender amps of the time which used 6V6's, but it was probably more like they were plentiful and at good price at the time

From memory the PYE HF5/8 used a pair of EL90's.

Terry

GrimJosef · 12th Aug 2018, 9:32 pm

Quote:

Originally Posted by Edward Huggins

... No matched pair here then ...

They could be (apart from the ink). The valve museum entry for the EL90 http://www.r-type.org/exhib/aad0125.htm shows that Brimar made them and printed either EL90 or 6AQ5 on the outside, presumably in response to what their bulk customers asked for.

Cheers,

GJ

trickie_dickie · 12th Aug 2018, 9:34 pm

This one?

joebog1 · 12th Aug 2018, 10:08 pm

6AQ5s were very common in Australia. They are a 6V6 in a seven pin bottle but have maximum (recommended) HT of 250 volts. They sound delicious, just like a 6BW6, 6V6, 7C5 or 6AQ5/EL90. It will be a very nice little amp. In theory its good for about 10 watts RMS.

Joe

Diabolical Artificer · 13th Aug 2018, 6:44 am

Your amp looks exactly like the one in the main pic on the WEM site -
http://www.vintagehofner.co.uk/brita...stminster.html it has the same bare patch on the corner and the dinks in the speaker grill match up.

Can't find a schematic but yours looks to be the same as this one - http://wem-owners.com/combos/westmin...tminster-1968/ which gives the date as 1959, so it's a very early one.

The schematic in post #15 looks to be about the nearest you'll find for the OP stage. I'd guess the EF86's are a mic preamp section. does it have a tremelo?

Andy.

Craig Sawyers · 13th Aug 2018, 7:31 am

Ah - the late great Charlie Watkins; WEM stands for Watkins Electronic Music. Died in 2014 at age 101. Around 20 years ago I fixed up a Dominator Bass cabinet for my son, and Watkins was still answering the phone well into his 80's!

You'd need a purple phone to get him now, alas.

Craig

12th Aug 2018, 2:58 pm	#2
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Watkins Westminster valve amp I can't find anything about that chassis that's shown for the Westminster, but I'm no expert. Lawrence.

12th Aug 2018, 3:18 pm	#3
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,328	Re: Watkins Westminster valve amp That's a lot of valves for a single ended EL90 amp. Maybe they are used for effects or the OP has the line up wrong? __________________ Edward.

12th Aug 2018, 3:29 pm	#4
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Watkins Westminster valve amp I think a 6AQ5 is an equivalent to the EL90. Which, given one of each in the lineup, suggests it could be a push-pull output stage using those 2 valves

12th Aug 2018, 3:44 pm	#5
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: Watkins Westminster valve amp Not found a schematic but this page gives more details about the Westminster models. http://www.vintagehofner.co.uk/brita...stminster.html Al __________________ I won't tell you how I discovered that.

12th Aug 2018, 3:51 pm	#6
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Watkins Westminster valve amp The output transformer looks like a Radiospares Hygrade…? Lawrence.

12th Aug 2018, 1:50 pm	#1
recordplayer Pentode Join Date: May 2010 Location: Preston, Lancashire, UK. Posts: 156	Watkins Westminster valve amp Hi, I am repairing a Watkins amp - even though it works I am going to change all the Hunts caps, and the electrolytics, and any resistors that are out of tolerance. I think it dates back to about 1956 and the valve line up is: 2x ECC83, 1X 6AQ5, 2XEF86, 1XEL90, 1X EZ80 which I will also check out. Does anyone have the schematic / circuit diagram or know the exact model - see pics. Attached Thumbnails

12th Aug 2018, 7:23 pm	#7
buggies Heptode Join Date: Jan 2009 Location: West Lothian, UK. Posts: 761	Re: Watkins Westminster valve amp Again no schematic but the third picture in post #1 looks identical to this one on the site mentioned by Alistair D http://www.vintagehofner.co.uk/brita...er/west21.html c1956 WATKINS WESTMINSTER AMPLIFIER COURTESY OF MICHAEL KERR, ESSEX, ENGLAND: and the internals:- http://www.vintagehofner.co.uk/brita...er/west19.html __________________ George

12th Aug 2018, 7:23 pm	#8
recordplayer Pentode Join Date: May 2010 Location: Preston, Lancashire, UK. Posts: 156	Re: Watkins Westminster valve amp Edward , with all due respect the valve line up is correct - when I said I would check the valves I meant the condition of the valves not the line up . Yes there are a few valves but they are the right ones - if you read my post it says the amp is working - so they can't be the wrong valves !

12th Aug 2018, 7:45 pm	#10
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Watkins Westminster valve amp Cheers, it was the colour on the label that made me think it might be RadioSpares, followed by the 6 tags on one side. Lawrence.

12th Aug 2018, 8:00 pm	#11
recordplayer Pentode Join Date: May 2010 Location: Preston, Lancashire, UK. Posts: 156	Re: Watkins Westminster valve amp Hi , yes I checked vintage Horner , I guess the 1956 one is the closest to mine - will work off that schematic - very similar to mine

12th Aug 2018, 9:25 pm	#13
Valvepower Octode Join Date: Aug 2008 Location: Rayleigh near Southend-On-Sea, Essex, UK. Posts: 1,880	Re: Watkins Westminster valve amp Hi, According to the r-type valve site the EL90 design is the classic 6V6 squeezed into the tiny B7G envelope! Maybe they were trying to get near the Fender amps of the time which used 6V6's, but it was probably more like they were plentiful and at good price at the time From memory the PYE HF5/8 used a pair of EL90's. Terry

12th Aug 2018, 9:34 pm	#15
trickie_dickie Hexode Join Date: Jan 2011 Location: Aberdare, South Wales, UK Posts: 403	Re: Watkins Westminster valve amp This one? Attached Thumbnails __________________ Richard

12th Aug 2018, 10:08 pm	#16
joebog1 Banned Join Date: Jun 2015 Location: Mareeba, North Queensland, Australia Posts: 2,704	Re: Watkins Westminster valve amp 6AQ5s were very common in Australia. They are a 6V6 in a seven pin bottle but have maximum (recommended) HT of 250 volts. They sound delicious, just like a 6BW6, 6V6, 7C5 or 6AQ5/EL90. It will be a very nice little amp. In theory its good for about 10 watts RMS. Joe

13th Aug 2018, 6:44 am	#17
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,662	Re: Watkins Westminster valve amp Your amp looks exactly like the one in the main pic on the WEM site - http://www.vintagehofner.co.uk/brita...stminster.html it has the same bare patch on the corner and the dinks in the speaker grill match up. Can't find a schematic but yours looks to be the same as this one - http://wem-owners.com/combos/westmin...tminster-1968/ which gives the date as 1959, so it's a very early one. The schematic in post #15 looks to be about the nearest you'll find for the OP stage. I'd guess the EF86's are a mic preamp section. does it have a tremelo? Andy. __________________ Curiosity hasn't killed this cat...so far.

13th Aug 2018, 7:31 am	#18
Craig Sawyers Dekatron Join Date: Nov 2010 Location: Oxford, UK. Posts: 4,984	Re: Watkins Westminster valve amp Ah - the late great Charlie Watkins; WEM stands for Watkins Electronic Music. Died in 2014 at age 101. Around 20 years ago I fixed up a Dominator Bass cabinet for my son, and Watkins was still answering the phone well into his 80's! You'd need a purple phone to get him now, alas. Craig