117 volt transformer for a Marshall Valvestate VS100R

[Sethkomar01]

Hi guys, I am new to the forum!

One quick question. I just purchased a valvestate VS100R amp that has a 230 volt transformer. I live in Canada and would like to get the 117 volt version of the power transformer. It is a Drake with part number 96B-4. Would anyone know where I might find one? So far I have had no luck. Thanks very much!

[nickb]

How about you use an external 117v to 230v transformer? The higher frequency won't do any harm.
Try http://www.jameco.com and search for vc-100

[Enzo]

I don't know either way, but contact a Marshall parts seller and find out if Marshall still has them.

for example Guitar, Amplifier, and Korg Keyboard Parts | NATIONAL PARTS DISTRIBUTOR FOR KORG, VOX, BLACKSTAR. PARTS FOR FENDER, GIBSON, GRETSCH, HOFNER, SWR, GUILD, AND MUCH MORE

CONTACT them and ask, don;t just look at the web site listings. Such listings are not their entire inventory.


Nick's idea also works, but requires having the external stepdown transformer to lug around.

[Sethkomar01]

Hey nickb, thanks for the quick response. That is most definately an option. I have already looked at one. I was just hoping to find the PT so I didn't have to carry around the step up. If I gotta go that route, I will. Cheers!!

[Sethkomar01]

Hi Enzo, thanks for the response! Already ahead of you. I actually contacted the site you had as an example. I gave them the part number and amp model and John Sprung got back to me and said he doesn't carry that transformer any longer. I couldn't find any other sites so I thought I would try here. May be lugging around a step up! Oh well, got the amp cheap and it is in great shape!
Thanks again and Cheers!

[Enzo]

We don't give up so easy...

The VS100 transformer is not stocked. Look at the schematics for more recent models like AVT100 and AVT150. They also are solid state amps with a single tube. AVT50, but I think that trnasfomer would be anemic for you. Either of those AVT PTs might be made to work. They have a high voltage winding for the tube. and a split winding for the power amp. The VS100 has a heater winding for the tube. Look at the newer models, they elimiate the heater separate winding by deriving a DC heater voltage from one of the low voltage supplies. SO I don;t think it would be hard to adapt one of these, probably the AVT100. I can't tell you if the dimensions would conveniently fit, but that research could be done.


And if all you want to do is save the amp, a regular solid state amp power tranny would probably work. Something for the power amp, and something for the low voltage circuits, common enough. Then a small auxiliary tansformer to make 300v or whatever. remember the tube only ever draws maybe 3-4ma tops, so a tiny transformer would work.


And that is just looking at Marshall products.

[J M Fahey]

Post the schematic to see what it actually uses, but consider that the older Valvestate 8080/8100 used a standard 30+30V 150VA Drake transformer whose equivalent is very common and easy to find.
And what about the tube?:
They used a small autotransformer (30VAC to necessary HV) for the tube +B and fed the 12V series connected filament from the +40V rail, with a suitable series dropping resistor.
Never saw the VS100R schematic, so I don't how much it differs from the earlier (VS8100) version, but this shows how Marshall themselves "improvised" using a generic transformer (maybe they had a warehouse full of them )

[Enzo]

OK, here...

[g1]

said he doesn't carry that transformer any longer. I couldn't find any other sites so I thought I would try here.

That doesn't necessarily mean they are no longer available although that could be the case.
You are in Canada, Erikson Canada now owns all Noth American distribution of Marshall. So you should at least check with them to see if it is still available. They have a service centre in Montreal and I doubt they would send back customers VS100's and tell them they are not repairable.
Send an email to the address 3rd from the bottom of this page: FAQs - Erikson Music
Ask them if the part is still available, tell them where you are and ask if you can buy direct from them or if they can recommend a dealer in your area.

[Jazz P Bass]

Here is a little Ampage snipit on the voltages.

1/22/2005 3:56 PM
Tiago Pires

--------------------------------------------------------------------------------
The transformer has a 35-0-35 winding, a 12V winding and a 270V winding. If you need the DC voltager, multiply them by 1.44. eg: VDC= VAC*1.44.

[nickb]

Ahem..well I have to issue a caveat. Maybe I was half asleep but I see the VC-100 is only 80W. You probably should go for the 300VA GPC-1003R.

Nick

[Sethkomar01]

Hey guys, thanks for all the info! You have given me some cool ideas if I can't get the proper PT. I may turn this into a project! Thanks for posting the schematic Enzo. I looked at the 8100 schematic that Juan mentioned and see how the dual transformer is setup. Jazz, thanks for the specs on the PT I am looking for. G-one, I just fired off an email to Erikson. I'll let you guys know the response. I am glad I stumbled on this forum. You guys are a great resource!

[Sethkomar01]

No problem Nick. I figured that was a typo. I knew what you were after.