I'm finally getting ready to finish building my SE it's been populated for years but life got in the way. With the TSE repaired and back up and running my attention is back on the SE.
I've been thinking of using either Antek or Toroidy transformers but they are both 30w models and I'm not sure if they are to big for the job.
Any helpful thought?
I've been thinking of using either Antek or Toroidy transformers but they are both 30w models and I'm not sure if they are to big for the job.
Any helpful thought?
I think the main benchmark is the DC current they can handle. What will be the current through the 45?
If your asking what they are biased for I believe mine were 27ma. It has been a long time since i went through final checks on that board. If your asking about something else, i apologize but im still learning all this.
And the ouput transformer I'm looking at can handle 150ma of dc current.
I have not tried any of the OPT's from Antek. I know from these forums that there were issues with their early SE OPT's.
There are lots of things called 30 watt OPT. Most of them are not right for a 45 tube. My pair of Hammond 1628SEA's are rated for "30 watts" They weigh about 12 pounds each. Flipping magnetic domains back and forth in that much iron will use up half of the power available from a 45 if not more. They however, unlike several transformers that I have will actually pass 30 watts of audio at 30 Hz. I have some 4 pound Eastern Audio transformers that claim "50 watts." They will indeed pass 50 watts at 1 KHz, but struggle to pass 5 watts at 30 Hz.
I have two pair of Toroidy SE OPTs. The 60 watt 6C33CSEs work well at 25 watts. I wouldn't use them at 60. The 60 watt KT88PSE are similar. I have not tried either of these in a low powered SE amp. Both were purchased for TV sweep tube or mosfet powered SE experiments. They sound better than any conventional OPT that I tried in those experiments.
The TTG-EL84SE is probably a good choice for a 45, but I have never actually tried them.
There are lots of things called 30 watt OPT. Most of them are not right for a 45 tube. My pair of Hammond 1628SEA's are rated for "30 watts" They weigh about 12 pounds each. Flipping magnetic domains back and forth in that much iron will use up half of the power available from a 45 if not more. They however, unlike several transformers that I have will actually pass 30 watts of audio at 30 Hz. I have some 4 pound Eastern Audio transformers that claim "50 watts." They will indeed pass 50 watts at 1 KHz, but struggle to pass 5 watts at 30 Hz.
I have two pair of Toroidy SE OPTs. The 60 watt 6C33CSEs work well at 25 watts. I wouldn't use them at 60. The 60 watt KT88PSE are similar. I have not tried either of these in a low powered SE amp. Both were purchased for TV sweep tube or mosfet powered SE experiments. They sound better than any conventional OPT that I tried in those experiments.
The TTG-EL84SE is probably a good choice for a 45, but I have never actually tried them.
This is one of the transformers I was looking at. The main reason i was interested is the wider frequency specs compared to edcore. Im not interested in more power just better sound output. And of course the price is attractive as well.
My first 45 powered TSE used Electra Print OPT's. I still have that one because it was the first one. My second TSE used Edcor XSE15-8-5K low budget OPT's. The Electra print amp was built in 2005 and the Edcor version was built in 2006. Oddly, I liked the Edcor amp better and both amps measured about the same with a bit better low end on the EP's but my 90's vintage Yamaha NS-10's have no response below 70 Hz. I don't think EP's are available today, and I don't know if Edcor changed the transformers since 2006, but they did change the price. They were $30 each, now they are $50 each.
Actually I have a pair of these that I purchased for this amp and used while going through the final check. They sounded ok from what i remember. I just figured I can afford to buy slightly better ones now and started looking.
As I understand it, when it comes to SE, bigger ain't necessarily better. A bigger transformer could be harder to drive effectively by the 45, and the flatness of the frequency response could suffer. I think there are notes about this on the Tubelab site.
I have the impression that a 45 is a special tube, and becoming increasingly rare, so maybe investing in a better quality transformer that is more optimal for the DC current of that tube is better. Something like Lundahl for example? There was a discussion about transformer manufacturers on the main board not so long ago, and it did not look like there were so many in The States these days.
There is also this thread: Output Transformer for 45
I have the impression that a 45 is a special tube, and becoming increasingly rare, so maybe investing in a better quality transformer that is more optimal for the DC current of that tube is better. Something like Lundahl for example? There was a discussion about transformer manufacturers on the main board not so long ago, and it did not look like there were so many in The States these days.
There is also this thread: Output Transformer for 45