Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: garyboy on November 20, 2012, 01:02:23 pm

Title: HAMMOND 100W OT tap question
Post by: garyboy on November 20, 2012, 01:02:23 pm
I am looking at a hammond 100W OT P-T1650R on TUBESANDMORE.COM. The description for the tranny says it has 4/8/16R impedance on the secondary and it's CT is 5000R. When you look at their diagram for the OT it show's 0/4/8R and a 0/4R secondary taps. How would you wire this for 16R operation if there isn't a 16R tap like they say it has?
Title: Re: HAMMOND 100W OT tap question
Post by: sluckey on November 20, 2012, 01:48:50 pm
You would have to go to the hammond website and look up that transformer. Then you would find the wiring diagram (see attached pic). If you are considering the 1650R OT may I suggest getting the 1650RA instead? It has a straightforward (easy wire) secondary. I hate those OTs that require a jumper kludge to get what you want. That really complicates switching impedance.
Title: Re: HAMMOND 100W OT tap question
Post by: stratele52 on November 20, 2012, 04:34:13 pm
garyboy ,

The P-T1650R is a linear transfomer . Kind of transformer the worst Fender Silverface's amp have.

Why don't you order Hammond 1700 serie ? That's the real tube classic for guitar amp.
www.hammondmfg.com/guitarLineOT.htm (http://www.hammondmfg.com/guitarLineOT.htm)

I don't know why Antique Electronics Supply ( tubesandmore) don't have this serie.

Few weeks ago I ordered an 1750G from my hammond distributor.
Title: Re: HAMMOND 100W OT tap question
Post by: clyde on November 20, 2012, 04:57:36 pm
I've used the 1650R and it's a great transformer.  Just because the U/L taps are there it doesn't mean you can't use pentode hook-up, and with a DPDT switch you can experience that Silverface nostalgia at your convenience.     
Title: Re: HAMMOND 100W OT tap question
Post by: stratele52 on November 20, 2012, 05:12:24 pm
I don't talk about the early 70s Siverface wich are like Blackface ,very good.  I talk about the mid and late 70's  silverface.  There are no nostalgia about those one.

Ultralinear are costly too

Hammond list price ;1650R   $190 and  in direct replacement  the  1750W is listed at $116
Title: Re: HAMMOND 100W OT tap question
Post by: clyde on November 20, 2012, 08:59:49 pm
'Twas a joke my friend.  On a more serious note, nothing in the 1700 lineup has 5k primary at 100 watts if that's what the OP was looking for and indeed it was what I needed for a pair of KT88's.  Switching secondaries is easy with Hammond's rotary impedance switch.    
Title: Re: HAMMOND 100W OT tap question
Post by: stratele52 on November 21, 2012, 04:53:21 am
'Twas a joke my friend.       

Tumbs up .

 
Title: Re: HAMMOND 100W OT tap question
Post by: garyboy on November 21, 2012, 08:46:09 am
I see thanks Sluckey. I wasn't sure if i was understanding the diagram because i was low on coffee and it was late when i looked at it or just being dumb. I also saw they offer a prewired impedance selector for those style hammonds.
Title: Re: HAMMOND 100W OT tap question
Post by: worth on November 21, 2012, 04:24:31 pm
AES DOES carry the 1700 series.
Title: Re: HAMMOND 100W OT tap question
Post by: HotBluePlates on November 21, 2012, 08:43:29 pm
Ultralinear are costly too

Hammond list price ;1650R   $190 and  in direct replacement  the  1750W is listed at $116

The 1650R is a bigger, heavier transformer, with a wider full-power frequency range and has a much bigger core.

1650R: 30Hz-30kHz, 12 lbs (but 5k primary)
1750W: 70Hz-15kHz, 4.5 lbs

The 1650T may be a better comparison, at 1.9k primary and 14 lbs.

The bigger Hammond may be "too good" for classic guitar sounds.
Title: Re: HAMMOND 100W OT tap question
Post by: DummyLoad on November 27, 2012, 04:59:42 pm
92 clams. ya gotta wait though.

http://www.edcorusa.com/p/459/cxpp100-ms-5k (http://www.edcorusa.com/p/459/cxpp100-ms-5k)

--DL