I did a little work on my DCG3 this weekend. Fitted the talema trafos and finslly added a small separate trafo for the In-select. I didn't like how I'd tapped off from under the DCSTB
Also I split the psu as the inner transistors do get a lot hotter than the outers. It does seemed to have helped.
And so far it has been powered 24/7 since for a couple or 3 days; trafos are warm but nothing more. Seem to be coping.!
I have improved my soldering since I first built this and I did have an intermittent dodgy channel. I've resoldered the signal wires to the rcas from the In-select outputs and thats cured that.
I am.aware my signal ground is straight to the safety ground and so I may look to improve that, although it is dead silent!
Edit....I cant find my heavy crimpers hence the horrible blue and brown wiring at the distribution connector.!
Also I split the psu as the inner transistors do get a lot hotter than the outers. It does seemed to have helped.
And so far it has been powered 24/7 since for a couple or 3 days; trafos are warm but nothing more. Seem to be coping.!
I have improved my soldering since I first built this and I did have an intermittent dodgy channel. I've resoldered the signal wires to the rcas from the In-select outputs and thats cured that.
I am.aware my signal ground is straight to the safety ground and so I may look to improve that, although it is dead silent!
Edit....I cant find my heavy crimpers hence the horrible blue and brown wiring at the distribution connector.!
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Didn't see this until now. I usually size transformers like this:
Raw DC = +-22V
Current = 175mA
Raw Power = 44V * 175mA = 7.7W
Derated by factor of 1.6 to account for rectifier inefficiency = 12.3W
Double that to be conservative = 24.6W
That leads to 25VA per channel. In my builds, the Talemas (15Vx15V) run only slightly warm. Good luck getting them, though. Seems like COVID hit the factory or something, because they're out of stock globally.
Yup, thanks. I did see that, and I'm glad you found some.
I was recently working on a new project and went and ordered a lot of parts for another one of my Super Regulator boards. Then I went to Digi-Key and was appalled to find the power transformers were out of stock. Nothing else I can find anywhere will fit my boards.
Fortunately, as you say, I was able to find the RS branded units and snagged a pair of the last remaining stock. They're all gone now. Very frustrating.
I've shamelessly attached an image to prove the point, but mainly to show off my latest work, LOL.
Edit: A few weeks after getting the RS transformers, they sent me an email saying they won't do any more business with me until I send them a tax exemption certificate. I'm like, "Uh, I went to your website, clicked to buy, and gave you my credit card number. What did I miss?"
I was recently working on a new project and went and ordered a lot of parts for another one of my Super Regulator boards. Then I went to Digi-Key and was appalled to find the power transformers were out of stock. Nothing else I can find anywhere will fit my boards.
Fortunately, as you say, I was able to find the RS branded units and snagged a pair of the last remaining stock. They're all gone now. Very frustrating.
I've shamelessly attached an image to prove the point, but mainly to show off my latest work, LOL.
Edit: A few weeks after getting the RS transformers, they sent me an email saying they won't do any more business with me until I send them a tax exemption certificate. I'm like, "Uh, I went to your website, clicked to buy, and gave you my credit card number. What did I miss?"
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Yes, definitely agree. My first DCG3 is running the 18V transformers and I have about +-25V raw DC. Losing that extra four volts cuts my regulator dissipation in half. The pass transistors run hot in that unit. The one I built for Kevin uses the 15V parts and runs cooler. I decided not to worry about it because the transistors can take the heat. Die temperature should be well within limits even if the heatsinks are at around 150F, estimated by touch.
Edit: Hey, Salas. You might be interested to know that Kevin has my new "HPA1" and says he prefers the DCG3. He's been too slammed with work and life to write a review (in my thread). But he says the HPA1 has a little better detail and bass control, and is very quiet, but isn't as well fleshed-out in the midrange. So the score is 1-0, advantage Salas, LOL.
Edit: Hey, Salas. You might be interested to know that Kevin has my new "HPA1" and says he prefers the DCG3. He's been too slammed with work and life to write a review (in my thread). But he says the HPA1 has a little better detail and bass control, and is very quiet, but isn't as well fleshed-out in the midrange. So the score is 1-0, advantage Salas, LOL.
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That's odd. I don't see any stock here. Have you got a web link?
Edit: NVM, I went back to my old order and searched for it by RS part number. Strangely, it doesn't come up in their parametric search. Guess they want to keep it secret. I will see if I can order another pair.
Thanks for letting me know.
Edit: Ok, I ordered another pair. We'll see if they send them, LOL.
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Here's the link anyway but glad you found them.
https://uk.rs-online.com/web/p/toroidal-transformers/1243876
I always found it strange they are under their toroidal transformer section. You would have thought they would be under 'pcb transformers' really.!
https://uk.rs-online.com/web/p/toroidal-transformers/1243876
I always found it strange they are under their toroidal transformer section. You would have thought they would be under 'pcb transformers' really.!
Thanks. I appreciate it, but that's ok. On further investigation, they are posting a general message about "operations issues" and some things seem broken on the website. I think maybe they are having a technical problem. It seems more likely they would simply send me an email, rather than wiping my history off the site without warning. They do say orders will be delayed by 3-4 days.
Apologies for the off-topic comments, but given the challenge of sourcing parts these days, it's not entirely irrelevant to prospective DCG3 builders.
I was very happy with the service I got on my last order, and the whole transaction went down as quickly, and for less cost, than if I had ordered from Digi-Key.
The shopping cart explicitly states that RS doesn't collect export tax, but it seems really odd to me that they are running this operation with international scope, yet don't have a process in place to support non-commercial buyers. I had no idea prior to my first order that there was any issue at all and am hoping my orders are small enough to fly under the radar. I don't mind (mostly) paying my taxes. Getting the parts I want is my priority.