Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: worth on July 13, 2011, 11:24:51 am

Title: DeArmond R15T schem ?
Post by: worth on July 13, 2011, 11:24:51 am

I'm seeing the volume pots as being 350K , and the treble pot 650K.... correct, or not ?

Title: Re: DeArmond R15T schem ?
Post by: Tone Junkie on July 13, 2011, 02:13:05 pm

yea Ive never seen a schematic that read .35M before but that would be 350k so correct as far as I can tell.
Thanks Bill

Title: Re: DeArmond R15T schem ?
Post by: DummyLoad on July 13, 2011, 02:51:27 pm

yes, pots are 650K and 350K.

make a 650K use a 1M pot paralleled with a 1M8 resistor.

make a 350K use a 500K pot paralleled with a 1M2 resistor.

--DL

Title: Re: DeArmond R15T schem ?
Post by: moonbird on July 13, 2011, 03:43:39 pm

Hi all --

Appears that Mercury Mag DOES supply PT & OTs for the push pull Dearmonds - I am attaching files. No SE OT though  :sad2:. Oh well there are MUCH cheaper options for that  :icon_biggrin:.

Title: Re: DeArmond R15T schem ?
Post by: worth on July 14, 2011, 07:10:49 am

The HV secondary is too high on the Toneclone to match the voltages on the schematic, ( if Martins' voltages are correct )... I'm thinking more like 260-275 V.

Title: Re: DeArmond R15T schem ?
Post by: Willabe on July 14, 2011, 07:24:12 am

It also has the 6.3 @ 5A?   2 - 6V6's = .9A, 3 - 12_ _7's =.9A, so .9A + .9A = 1.8A.

Might be they have their spec sheet's mixed up?


           Brad       :dontknow:   

Title: Re: DeArmond R15T schem ?
Post by: worth on July 14, 2011, 07:28:39 am

I read that the transformers were beefed up to allow for the use of 6L6s' or 6V6s'.

Title: Re: DeArmond R15T schem ?
Post by: Willabe on July 14, 2011, 07:36:58 am

Yeah but, 2 x 6L6's = 1.8A, so 1.8A + .9A = 2.7A. Still 2.3A extra, almost double in reserve.


            Brad         :dontknow: