Sonic difference between Marshall and Fender OT(with 6l6s)?

[Charlie Wilson]

Hello, I have been reading through some old posts and found that Gil (and Dumble in his later amps) like(d) to use Marshall output transformers. I know the primary impedance is supposed to be 2k for a Twin and 1.7k for a Marshall but I measured a Heyboer and a vintage Twin and got exactly 1.7k for both. So the question is what would be the difference in sound between the two? Maybe Dumble only used it to get a multi tap OT?
CW

[Guy77]

I use a Hammond Marshall JCM800 style output transformer (1750N) with my 50 watt ODS 124 clone and really really like it! I had 4K output transformer in there before and found that I liked it more with the marshall style 3.2K primary. I also use a Hammond marshall style choke. Hard to explain, bass sounded deeper i guess. One mans gold another mans garbage lol. I also use my amp in overdrive mod all the time.

Just my 2 cents.

keep the iron hot
Guy

[Charlie Wilson]

Thanks Guy. That is interesting. What got me to thinking about this is that I know some Dumbles run a 4 ohm transformer into an 8 ohm load. I do not care for this but I thought a slight mismatch might sweeten the highs a little and add a little compression. I also found an old post about #124s OT and how it might have been modified to lower the primary impedance. I think Marshall iron also has more iron that might give it more bass response.
CW

[Guy77]

Ok this is great, I just turned my output transformer switch from 8 ohms to 4 ohms (I run a 8 ohm speaker) and the highs do sound brighter and have more sparkle! Yes Charlie you are right about my Marshall style output transformer, it does have a bit more iron than the 4k primary transformer.

Cheers

Guy