NAD 1972 Model 1986

Matthews Guitars

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The current transformer may be just fine. But for the sake of doing the job right, be sure that the transformer is remounted with the proper
reinforcement bracket attached to the base of it.

Metropoulous has the brackets.

Example here.

1669351902126.png
 

FleshOnGear

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Anyone have an opinion on this brand of Power Transformer for the amp?

(If a replacement needs to be used).


Pacific Audio Magnetics

Marshall 50 Watt Power Transformer
50 WATT, Drake, JCM800, JMP 50W
Drake PN: 1202-324
[PAM-PT-50-36R]
$147.00
As said above, the transformer you have may be fine. It looks like your amp used to have a laydown transformer, which probably would’ve been the 1202-118. Mermen and Marstran make a 1202-118 clone, but the prices aren’t on their websites.
 

Central Scrutinizer

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@Gene Ballzz , yes I got it it looks great.

I have not fired it up yet after reading some stories regarding wall voltage, versus the proper/made for amplifier voltage. My wall voltage is between 110-124 V.

I have made up light bulb limiter and have a Brown Box incoming. Taking every precaution before “firing it up”. Probably silly of me, but I like to take care of my things, “an once of prevention,...”.

Thanks for asking Gene. Will keep you in the loop.
 

FleshOnGear

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@Gene Ballzz , yes I got it it looks great.

I have not fired it up yet after reading some stories regarding wall voltage, versus the proper/made for amplifier voltage. My wall voltage is between 110-124 V.

I have made up light bulb limiter and have a Brown Box incoming. Taking every precaution before “firing it up”. Probably silly of me, but I like to take care of my things, “an once of prevention,...”.

Thanks for asking Gene. Will keep you in the loop.
Can’t wait to hear how you like it!
I picked up a ‘72 1987 earlier this year and I love it.
Congrats!
 

AndyD

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It’s all about the B+. Your amp would originally have a B + of between 370 -420v.….more likely the later. Have you a date printed on the mains transformer? Either way, I would stick with what you have unless you specifically want a lay down transformer in which case Marstran is the way to go.
 
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TM1

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I think I told you I had one exactly like yours, even Q.C.'d on the same day. I wouldn't replace the Mains tranny unless it goes, and then I would have it rewound to keep the amp original. Mine had a replaced Mains. Originally it was a laydown, but whomever did the work used a standup. The B+ was like 440v
The one I got I bought from a friend in Manchester(U.K.) for a rediculous amount. Of course it was in 1997 and Marshall 2nd hand prices were pretty low.
Anyway, enjoy it!
 

neikeel

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I think I told you I had one exactly like yours, even Q.C.'d on the same day. I wouldn't replace the Mains tranny unless it goes, and then I would have it rewound to keep the amp original. Mine had a replaced Mains. Originally it was a laydown, but whomever did the work used a standup. The B+ was like 440v
The one I got I bought from a friend in Manchester(U.K.) for a rediculous amount. Of course it was in 1997 and Marshall 2nd hand prices were pretty low.
Anyway, enjoy it!
I agree ith your sentiments entirely but that PT is not original to that amp.. It is clearly a replacement (of a slightly later type) as the original was a laydown and the wiring has been spliced in.
There is little doubt that other than a spare 1202-118 Drake the most accurate clones are Marstran and Merren (when you can get hold of him!). I am sure Mercury make great PTs but based on my (admittedly limited) experience with Mercury I think that they are overpriced, but if you have a deal with them of course go for it.
 

playloud

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Anyone have an opinion on this brand of Power Transformer for the amp?

(If a replacement needs to be used).


Pacific Audio Magnetics

Marshall 50 Watt Power Transformer
50 WATT, Drake, JCM800, JMP 50W
Drake PN: 1202-324
[PAM-PT-50-36R]
$147.00

If you don't want to wait for Marstran, this looks like a Heyboer version of a 1202-118: https://shop.amppartsdirect.com/pro...pgrade-apd-8089-h?_pos=2&_sid=3a6f57188&_ss=r

I would be wary of Pacific because of their loose adherence to TW specs, but admit that isn't much to go on.

However, I agree with posters above that the current PT may be just fine. Measure the B+ after you fire it up.

@Gene Ballzz , yes I got it it looks great.

I have not fired it up yet after reading some stories regarding wall voltage, versus the proper/made for amplifier voltage. My wall voltage is between 110-124 V.

I have made up light bulb limiter and have a Brown Box incoming. Taking every precaution before “firing it up”. Probably silly of me, but I like to take care of my things, “an once of prevention,...”.

Thanks for asking Gene. Will keep you in the loop.

I would strongly suggest a variac over a Brown Box. Being able to have the full, continuous range of output voltages is really useful (I used mine set to 10V to measure winding ratios on an unknown PT the other day), and they cost less. The BB appears to be aimed at players who don't have much technical knowledge/interest. They just want something they can plug into with peace of mind while playing, and for that purpose it is fine.

Let us know how you get on!
 

Derrick111

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I'd go with Mercury for the PT it was me.
I am sure Mercury make great PTs but based on my (admittedly limited) experience with Mercury I think that they are overpriced, but if you have a deal with them of course go for it.
Mercury makes a quality transformer, but the sound is stiff/clinical/sterile... that is exactly what you don't want and the oposite of why you likely wanted that kind of amp in the first place. Kind of an ironic company existence for that reason. To add insult to injury, they are priced stupid high.
 

Gene Ballzz

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Mercury makes a quality transformer, but the sound is stiff/clinical/sterile... that is exactly what you don't want and the oposite of why you likely wanted that kind of amp in the first place. Kind of an ironic company existence for that reason. To add insult to injury, they are priced stupid high.

That Sir, is nearly word for word what I generally hear & read about MM transformers and even a bit more so when discussing their output transformers! Am I the only one who truly misses ClassicTone? :(
Just Transformin'
Gene
 

Derrick111

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That Sir, is nearly word for word what I generally hear & read about MM transformers and even a bit more so when discussing their output transformers! Am I the only one who truly misses ClassicTone? :(
Just Transformin'
Gene
No, you are absolutely not the only one who misses Classic Tone transformers! Also, remember OEM transformers from the mid to the early 2000s? Another great transformer maker now gone. There was such feel, character yet high quality in those options. We really are due another good potion for Marshall replacements/builds... Merren is hard to reach and highest price, but you get what you pay for! I don't have enough experience with Marstran to know how "organic" like the originals they are, or how much the Schumacher (the Fender transformer maker) captures the original Marshall spirit either... Too bad you cant get the Drake that were available until a few years ago at least.
 

Gene Ballzz

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I'm not sure that I've seen any "definitive" identification of the current PT and how it and it's specs compare to the one that came originally in this amp? Might that be helpful to know? Mounting and tidying up the wiring is a piece of cake, as long as the transformer can "do the electrical due!"
Just Curious & Askin'
Gene
 

Central Scrutinizer

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I think I told you I had one exactly like yours, even Q.C.'d on the same day
While looking for comparable signatures for the inspection sticker affixed to my amp, I came across this example on Amp Archives, is this yours?

From Amp Archives: S/N SA1130D

7734F981-D17D-472F-A4A2-629D5BED9B1F.jpeg
__________________________________________________________

Mine below:


6B2AC5E5-DAE3-4F51-9608-BDF7563BB1FD.jpeg
 

Central Scrutinizer

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Attempted to get some pictures of the PT to figure out the manufacturer.
I though there would be some numbers that I could read to obtain who the maker is.

The only thing I have noticed that differs from the Sellers pictures are two places where it looks like labels of some-type were affixed.

One looks like it had a square label attached on one side and a rectangular label on the other side of it.

8CF0CFF1-E4F6-4E24-865C-135E91308099.jpeg



2D80E1E6-4923-4404-BDF7-7B3080958ED2.jpeg

I know this is not much help, but I thought some of you may recognize the residual label size and placement to possibly ID a brand.
 
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Central Scrutinizer

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While I had the chassis out of the head box, I took pictures of the inspection label.

Thought it was weird that there was not a name as to who did the back panel inspection work / inspection.

Upon comparing this to the sellers pictures, it appears there is a highly faded signature. Looks like someone may have cleaned the amp and possibly partially erased the signature. It appears some of the signatures were placed sing a fountain pen, with the older type of ink.

OK you Sleuths and Detectives, do you see it? If so, can you tell me who it is?

Thanks !

64AACAAD-1B01-4FA1-A0BA-D472D2B6EEFC.jpeg



971AB936-1BAE-4979-ACF3-5C3F664637F8.jpeg
 


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