Can sombody please explain re 6.6k, 8k & 9k Ohm primarys

pongo316 · Post by **pongo316** » Sat Apr 19, 2008 6:49 am

Mercury Magnetics RadioSpares Marshall JTM45 Output Transformer - O45RS-L

6.6k, 8k & 9k Ohm primary, 4 or 8 or 16 Ohm secondary taps

What are the different value on the primary for and what do they do and how do they affect the sound ?

confused

5150loveeddie · Post by **5150loveeddie** » Sat Apr 19, 2008 11:59 am

6.6k primaries will give you more headroom (cleaner and a little more volume), (rare)
8k will give you a little less headroom quicker clipping, (medium)
9k is the most gain, compression, lesser headroom (well done)

So you get to choose which one you want and hook the OT accordindly..., try them all and see which one you like/prefer.. The 9k is the dirtier one, but the tone get thinner also, I prefer the 6.6k....

So the more you go up 9k the more gainy it gets and vise versa, most JTM45 were hooked on 6.6k from the factory I beleive...

pongo316 · Post by **pongo316** » Sat Apr 19, 2008 5:43 pm

Thanks

the metro is the same I take it ?

I can run any of theres tubes with this kind of OT

But have to choose commit to a secondary s it is not swichable.

Metroamp Radio Spares De-Luxe Replica
[RS De-Luxe]

Wound to original specs for core stacking, laminations gauge, interleaves, bobbin material ect. This replica is suitable for early JTM 45's, Vox AC30's and many other British amps.

The Radio Spares De-Luxe model output transformer used a tag board with terminals, but we have wires for each primary and secondary connection.

The multiple impedance primary is suitable for all of the common guitar amp output tube types: EL84, 6V6, 6L6, EL34, KT66 ect.

The taps are:

6.6K (with 43% ultra linear taps)

8K

9K

Multiple secondaries can be wire for 4,8 or 16 ohm loads.

NOTE: solid color wires go to V4 pin 3 and striped wires go to V5 pin 3.