Mercury Magnetics or Heybouer transformer?

[s2]

1. The MM sample I have was machine wound on a plastic bobbin without interleaving. It is a fact. If you look at their web site, you can see the same contruction depicted in photos. It may sound fine as such. I thought is sounded pretty darn good myself. But I also think Hammonds sound good and are made with the same construction techniques. This is my opinion and I am certainly entitled to it.

Futher, any builder evaluating product for his own amps would act prudently to test everything available and make up his own mind based upon his own opinions anyway.

2. Someone asked if they should remove the nuts holding the bell cover and lam stack together and mount the PT flush against the chassis. As I recall, I said you can do that. I also said that "my tranny guy" tells me they torque those nuts to a specific pressure, which helps alleviate PT hum in some cases and it is best to leave them and use a second set of hardware unless you plan to torque them again after installation. He also said there is a tiny bit of risk that removing the nuts may upset the varnish.

[dboul]

1. The MM sample I have was machine wound on a plastic bobbin without interleaving.

That's not what they sell now for the 18watt. That's their old generic 18watt/20watt Marshall OT. They're only been selling their RS OT for a few months publicly.

Although, I think the bobbin is still plastic on their RS model. They have to keep them UL/CE compatible. A paper bobbin and an exposed tagboard on the top are not UL/CE acceptable. Both are technically speaking, a bit a of risk. Doesn't bother me at all, but you could imagine the lawsuit if someone arcs their finger across the tagboard. Not likely I know, but laywers would be losing sleep everywhere!

Cheers,

Dan