OT question

[redmax61]

I have a Dagnall 2505 that was taken out of a JTM45. I'm trying to find specs on it to see if I can use it in a 36w configuration using 4 EL84's. I've been finding similar transformers that say they can be used in both configurations, but no concrete specs on the Dagnall.

Is anyone familiar with this transformer?

[stevesuk]

Yes,
I have a Dagnall D2505 (Marshall JTM45 spares issue) in a stripper JTM45, which I may use in a 36W (4 X EL84) or a 2 X 6L6.
They are close enough to 4K to do the job.
Do you need the colour code for the leads ?

Steve UK
www.valvepower.co.uk

[zaphod_phil]

I don't see any good reason not use a JTM45 OT in a 36W. However, with the 8k primary, one would need to remember to run an 8 ohm speaker cab off the 16 ohm OT secondary tapping, or a 4 ohm cab off the 8 ohm tapping.

[stevesuk]

Amplifier Primary Impedance

Marshall, 50W 2xEL34 3,400 Ohms

Marshall 100W 4xEL34 1,750 Ohms

Marshall 18W 2xEL84 8,000 Ohms

Marshall 36W 4xEL84 4,000 Ohms

Marshall JTM45 2xKT66 8,000 Ohms

Vox 30W 4xEL84 4,000 Ohms

Vox 15W 2xEL84 8,000 Ohms

Fender 50W 2x6L6 4,100 Ohms

Fender 100W 4x6L6 2,000 Ohms

Tweed-Spec Cathode Bias 6L6 p-p 6,600 Ohms

Matchless 15W 2xEL84 4,000 Ohm

Matchless 30W 4xEL84 4,000 Ohms

Park 50W 2xEL34 5,000 Ohms
__________________
Originally Posted by Jon Silberman

Steve UK