Hi All,
I built my TSE-II last year with 300B tubes. I ended up using an Edcor XPWR008 for the power transformer (600V@200ma CT, 6.3V@4A, 5V@3A) as I found one used. Based on advice here, I used a Triad C17-X choke (1.5H@300ADC) with it, and get hum free sound and ~360V on the 300b plates.
I'm happy with the sound, but the power transformer has a mechanical buzz that has been driving me bonkers. I have tried rubber grommets for mounting, placing wedges between the end bells and the laminations, and finally lining the inside end bells with some sound dampening material, and nothing seems to work (In addition, it runs really hot).
Long story short, I'm going to replace it with another Edcor (I want to use the same mounting holes).
Do you think I should replace it with a new XPWR008, or get something with a higher CT voltage and replace the choke as well? I am guessing it's just a bad transformer, but I'm not sure if this setup is stressing it (that heat!) and the new one would do the same? I know a lot of people on here seem to go with more than 600V CT.
Any advice or recommendations appreciated -- thanks!
I built my TSE-II last year with 300B tubes. I ended up using an Edcor XPWR008 for the power transformer (600V@200ma CT, 6.3V@4A, 5V@3A) as I found one used. Based on advice here, I used a Triad C17-X choke (1.5H@300ADC) with it, and get hum free sound and ~360V on the 300b plates.
I'm happy with the sound, but the power transformer has a mechanical buzz that has been driving me bonkers. I have tried rubber grommets for mounting, placing wedges between the end bells and the laminations, and finally lining the inside end bells with some sound dampening material, and nothing seems to work (In addition, it runs really hot).
Long story short, I'm going to replace it with another Edcor (I want to use the same mounting holes).
Do you think I should replace it with a new XPWR008, or get something with a higher CT voltage and replace the choke as well? I am guessing it's just a bad transformer, but I'm not sure if this setup is stressing it (that heat!) and the new one would do the same? I know a lot of people on here seem to go with more than 600V CT.
Any advice or recommendations appreciated -- thanks!
It might be worth having a transformer manufacturer re-vacuum impregnate and heavy varnish dip the transformer. We used to manufacture 200kg voltage stabiliser transformers which were inaudible under full load unless you put your ear to them.
Thanks! I'd rather not be without a transformer for too long though, and i think if I buy a new one the manufacturer will at least replace it if it's noisy.
Take a look at the Edcor XPWR 131. It was designed for the TSE and should work with the TSE-II.
It has worked well for me in a number of builds. No buzz.
It has worked well for me in a number of builds. No buzz.
Thanks, didn't know about that one! I was thinking of the XPWR178 for a slightly higher current rating, but I like the idea of one that was designed for TSE.
jerkbag,
XPWR178 is a good choice too, especially with the the higher mA rating.
The XPWR131 has taps for 520V CT operation also, in case you want to go for a 2A3 or 45 tube.
XPWR178 is a good choice too, especially with the the higher mA rating.
The XPWR131 has taps for 520V CT operation also, in case you want to go for a 2A3 or 45 tube.
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I've also used the XPWR-131 on two TLSE 45 amps and two TLSE 300B amps. Nary a problem with any of them. Haven't tried them with 2A3.
The XPWR131 was indeed designed just for the TSE. It however was never intended for use with 2A3's as it does not have enough current capability on the 6.3 volt winding.
thanks for the info all. Slightly off topic: assuming one has appropriate Power and Output transformers, do any other major parts need to be swapped out to run 45 tubes? I know there are some small capacitors, resistors, etc. . but do the 45s use the same tube sockets?
The 45 needs 2.5 volts on the filament and about 275 volts on the plate supply. The 300B needs 5 volts on the filament, and about 375 volts on the plate supply.
The filament voltage is set by a resistor and jumper change. The plate supply can be changed by swapping the transformer taps with the XPWR131.
Do not fall for the temptation to make the swap easy with jumpers or switches. You will be very unhappy when you get it wrong and plug 45's into an amp set up for 300B's. They live less than one second.
Since I have several of both variations of the TSE boards I put a sticker on each board to remind me how the jumpers and resistors are set.
There is a tube called the NX-483, or just 483. It is a 45 with a 5 volt filament. They are pretty rare. I have a 92 year old pair in my original TSE. I have been running them on 325 volts for nearly 15 years and they are still rockin.
The filament voltage is set by a resistor and jumper change. The plate supply can be changed by swapping the transformer taps with the XPWR131.
Do not fall for the temptation to make the swap easy with jumpers or switches. You will be very unhappy when you get it wrong and plug 45's into an amp set up for 300B's. They live less than one second.
Since I have several of both variations of the TSE boards I put a sticker on each board to remind me how the jumpers and resistors are set.
There is a tube called the NX-483, or just 483. It is a 45 with a 5 volt filament. They are pretty rare. I have a 92 year old pair in my original TSE. I have been running them on 325 volts for nearly 15 years and they are still rockin.