Marshall voltage question

Whatwhatringrang

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Gene Ballz has some good points depending on how you plan on doing this. “The Name is Ballzz …..Gene Ballzz lol”:
 

Pete Farrington

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But then your neutral is 120v away from ground, which is not the way it works in the UK and could maybe be unsafe or cause who knows what issues for equipment that is expecting neutral and ground to be at nearly the same potential.
I don’t think it would cause any operational issues, but from a safety perspective, modern standards require both live feeds be fused and switched.
I suppose a workaround might be to do that at a dedicated wall outlet.
 

chocol8

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Modern standard it to switch the neutral as well, so both leads should be switched in a new amp. You could add a second fuse, but the outlet should be on a breaker that will trip if there is a short before the PT.
 

scottster

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Thanks all for the great input. Here's where I am so far. I just got the adapter from Amazon (NEMA 6-15 to UK 3 prong) I ordered prior to the warning by Spacerocker and am dying to at least make sure this thing amplifies a signal before I lose my return window. Spacerocker had some concerns about the secondary not being isolated from the primary and the Hammond being an auto- transformer but the LiteFuze step up voltage converter that Whatwhatringrang is using appears to not be isolated either- see last comment ( https://www.amazon.com/LiteFuze-LT-5000-Voltage-Converter-Transformer/dp/B008RO367U?th=1 ). Any thoughts?

Anyway, I'm going to at least try to see if I can get this thing to turn on and check signal by plugging a guitar cable in and putting my thumb on the other end of the jack to see if it buzzes. Wish me luck! I'll probably post results tomorrow due to schedule.

This just ran through my head thinking about plugging this thing in...

 

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Whatwhatringrang

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Lol 😂 Intense insanity in that clip. I bet that guy would have been a half decent frontman if he played music. Maybe he also does perform music?? Lol

I have never had any problems using that lite fuze one . Lots of hours through it . It runs a little cooler than using 120 if the amp has with certain amps.

Let me know if lightning strikes you down (or don’t I guess lol) . So I can prepare but getting my golf clubs out, radio antenna out and head up to the mountain/roof.
 

scottster

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Real Genius is a classic!

Here's the latest. I called Hammond and talked with a rep who said that as long as the unit that's being stepped up is isolated, there should be no problem although when I asked him if isolation/grounding is an issue, he said "oh yeah, this is an auto transformer" which jogged something in his mind. He went on to explain things that were beyond my understanding but ended up saying that stepping down might pose an issue but stepping up should not. His only concern was the amperage rating of the Marshall (I couldn't find it during the call) because the Hammond 176C is rated for 1.3 Amps. He also said not to plug a power strip into it and run other things off it which could increase the current draw past max.

I've been playing this amp for a few days now and it sounds great and is working great.

I emailed Dagnall asking if I can get a 120v transformer from them because it sounds like this is by far the best option moving forward. Haven't heard back yet.

I'm interested in the suggestions about seeing if this PT has a 120V tap- what would that look like? I'm imagining multiple tabs coming off the transformer that aren't attached to anything?
 

XTRXTR

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Sometimes manufacturers get cheap with the switches and just hard wire a single voltage even though the transformer is multi voltage.
Yes I see that a lot myself 🙂
I'm interested in the suggestions about seeing if this PT has a 120V tap- what would that look like? I'm imagining multiple tabs coming off the transformer that aren't attached to anything?
FYI I was looking at schems for 50W and found the three numbers listed next to one transformer. The 410 100W has four listed while the 50W has three. It is my belief these are listed as a note for the people on the line building the amps. I say that because they are still showing 100V, 117V, 130V, and 230V input taps each with a different number. I have difficulty believing that Marshall has an actual Part for a 100V or a 130V separately. It makes more sense that it would be one part and the MFR line connects taps according to import country. I say that because, what if they over buy a particular part for 100V for instance, now they have extra inventory they have to pay taxes on and can't use on other amps. It just doesn't make business sense to me.

You could open and check for extra wires tucked up next to the transformer where the wires that run back to the plug coming into the amp from the outside are located. It is also possible that there may be taps on the transformer that do not have a wire soldered to it. In other words it may have the tap but not wired. You would need someone that knows what to look for to locate it in that case and then solder on the tap wires correctly.

Also you need the proper north american IEC plug wired into the amp at the same time. If you wire a 240 outlet you need to get the proper US IEC male plug to the amp as well.
 
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scottster

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I found a local Marshall authorized service center and got a quote to change out the transformer so that's the direction I'm going to go. Thanks everyone for chiming in on this, much appreciated.
 

happyleon

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Scott
I found a local Marshall authorized service center and got a quote to change out the transformer so that's the direction I'm going to go. Thanks everyone for chiming in on this, much appreciated.
How much did they quote you? Is it a simple rewiring or is it a whole output transformer swap? Thank you!
 

neikeel

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Modern standard it to switch the neutral as well, so both leads should be switched in a new amp. You could add a second fuse, but the outlet should be on a breaker that will trip if there is a short before the PT.
It is mandatory to switch both if you have a fixed mains cord in (in the U.K. that is).
 

Gene Ballzz

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$175 for the 120v transformer and $75 install is what I was quoted.

Well, along with the initial international shipping, does that still leave you at a price point lower than the US retail number? If so, you've done well!
Just Sayin'
Gene
 

saxon68

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Well, along with the initial international shipping, does that still leave you at a price point lower than the US retail number? If so, you've done well!
Just Sayin'
Gene
If it’s anything like what I paid for my amp sourced outside the country, I paid $787 (including shipping) for an amp head that sells here in the US for $1,750, and I paid about $540 (including shipping) for a cab that sells for $1,200 here. The head was $45 to ship, the cab was an extra $34 to ship due to size/weight. Also spent about $40 for a voltage transformer, got a 300 watt unit since the amp is 20 watts.

So all in, including shipping and the transformer, I got the whole setup for $400 less than I would have paid for the head alone here.

FD6F8A23-1923-450A-B4CD-8C8C42F3E26D.jpeg
0399E772-CAAA-4823-A57C-D460D5F40621.jpeg

I honestly don’t know who is making the profits off the people paying full price but it’s a damn ripoff. I keep hearing about shipping and duty, but in my actual hands on experience it comes nowhere near what we’d pay.
 

chocol8

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Before airfares shot back up, you could have flown to the UK, spent a night in a hotel, and flown back with an amp and still come out ahead of the US pricing.
 

2L man

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Real Genius is a classic!

Here's the latest. I called Hammond and talked with a rep who said that as long as the unit that's being stepped up is isolated, there should be no problem although when I asked him if isolation/grounding is an issue, he said "oh yeah, this is an auto transformer" which jogged something in his mind. He went on to explain things that were beyond my understanding but ended up saying that stepping down might pose an issue but stepping up should not. His only concern was the amperage rating of the Marshall (I couldn't find it during the call) because the Hammond 176C is rated for 1.3 Amps. He also said not to plug a power strip into it and run other things off it which could increase the current draw past max.

I've been playing this amp for a few days now and it sounds great and is working great.

I emailed Dagnall asking if I can get a 120v transformer from them because it sounds like this is by far the best option moving forward. Haven't heard back yet.

I'm interested in the suggestions about seeing if this PT has a 120V tap- what would that look like? I'm imagining multiple tabs coming off the transformer that aren't attached to anything?
An auto transformer does not isolate Mains because it is just one coil which in this case has 115VAC input and 230VAC output. It is cheaper and lighter and therefore are manufactured. Usually it can be used both ways also feeding 230V outputting 115V.

True transformer has primary and secondary and isolation between them is rated for at least 1500V.

If your amp has an International transformer its primary has two coils which are connect parallel for NA use and series for Europe use. These coils might have 10V options too. Another international has only one coil which has at least two inputs. This is not as efficient way to build transformer because for 115V use the 115-230 section is useless. For 230V use the 0-115 section wire is unnecessary thick.

Resistance measuring will reveal this quite well if you find a "hidden" primary input which resistance is sometwere between 0 and 230V. Then Voltage measures will confirm this where it get placed between Mains feed. If if exactly in between and coils are possible to separate just connect them parallel moving both half ends towards other primary half. If primary has only one coil which has 115V input use the half which resistance is lower when it indicate that its wire is thicker or shorter length because it was wound first closests to the core. This 115V might not be exactly between 0 and 230V when you do voltage measuring.
 


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