Good Morning,
I have been an audio enthusiast for years but have never built my own or know the basics of tube amplification. I did however buy a finished tube kit from ebay that- although it sounds good and is working, the Transformer runs real hot. Maybe too hot? I have not been able to find the specs on this board and it is sold for 230v. The seller converted it to 110v.
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The one along1986090 sent is wired differently than the first with filament wires going directly to the tubes which I understand is correct? Remember 'noob'. Also the one pictured has 3 22uf capacitors and he installed 150uf.
What I'd like any info on is when you buy a kit that says 230v- what is the best way to go about powering it correctly? Use a 230V transformer with a step-up converter? etc. Just want to do it right.
Does anyone recognize this layout? I asked for a schematic and believe they sent the wrong one? Right now I consider this a test machine since I'd like to dig into it and if I blow it I blow it. I will be learning more about tube amplifiers but like I said this is ground zero jumping in-point for me.
Any insights welcome.
Xeta
I have been an audio enthusiast for years but have never built my own or know the basics of tube amplification. I did however buy a finished tube kit from ebay that- although it sounds good and is working, the Transformer runs real hot. Maybe too hot? I have not been able to find the specs on this board and it is sold for 230v. The seller converted it to 110v.
Commercial links removed by moderation Copyrighted photograph removed by moderation Commercial Links removed by moderationThe one along1986090 sent is wired differently than the first with filament wires going directly to the tubes which I understand is correct? Remember 'noob'. Also the one pictured has 3 22uf capacitors and he installed 150uf.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
What I'd like any info on is when you buy a kit that says 230v- what is the best way to go about powering it correctly? Use a 230V transformer with a step-up converter? etc. Just want to do it right.
Does anyone recognize this layout? I asked for a schematic and believe they sent the wrong one? Right now I consider this a test machine since I'd like to dig into it and if I blow it I blow it. I will be learning more about tube amplifiers but like I said this is ground zero jumping in-point for me.
Any insights welcome.
Xeta
The fact that the seller configured this unit for 120V operation makes the comments about 230V operation irrelevant - it is nothing more than a function of the transformer fitted or if it is a dual primary type whether the primary is wired in series for 230V operation or in parallel for 120V operation. You don't need to do anything.
How hot is the transformer running? If you can touch it without getting burned after several hours of operation it is operating in an acceptable temperature range. If you have a DVM with a thermocouple measure the temperature of the transformer after it has been running for a while.
How hot is the transformer running? If you can touch it without getting burned after several hours of operation it is operating in an acceptable temperature range. If you have a DVM with a thermocouple measure the temperature of the transformer after it has been running for a while.
Here is how it looked with 22uf caps. Isn't 150u a high substitute? Or do you think that's ok.
An externally hosted image should be here but it was not working when we last tested it.
a trafo burning a bit hot
and with just a preamp my guess heater/bias is causing it, but I don't much about it
is there something about oscillation could cause this ?
hmm, a trafo changed from 115V to 230V could mean half ampere rating, running on its limit ?
just a few 'options'
dzseki,
When I asked about replacing the transformer perhaps with a smaller because it was not mounted to the chasis and nearly touching cover- only taped :0 I was told a 30VA. Perhaps a 10-15VA less heat then? Here is the schematic they sent me for reference...
P.S. Forgive my noobness. But you gotta start somewhere. I'm pretty good at learning and I am excited about tubiness as it is new territory. It's funny after half a century on this rock and with SS I'm only tipping me toes into tubeland now. Feels good though.
When I asked about replacing the transformer perhaps with a smaller because it was not mounted to the chasis and nearly touching cover- only taped :0 I was told a 30VA. Perhaps a 10-15VA less heat then? Here is the schematic they sent me for reference...
An externally hosted image should be here but it was not working when we last tested it.
P.S. Forgive my noobness. But you gotta start somewhere. I'm pretty good at learning and I am excited about tubiness as it is new territory. It's funny after half a century on this rock and with SS I'm only tipping me toes into tubeland now. Feels good though.
Make note of how the transformer is connected to the PCB and then unsolder all of those wires and tape them off temporarily.
Next just plug in the transformer and wait a while and see if it gets hot.
A 30VA transformer should run fairly cool, if it does then there is probably an issue with a component on that PCB.. Should it run hot you will need to replace the transformer.. Measure the voltages on the secondary and buy a Hammond or Antek that is close.
If you are going to dabble with tubes you need a good DMM, decent temperature controlled solder iron, and appropriate hand tools. Also you should read the safety and high voltage threads associated with this forum.
Next just plug in the transformer and wait a while and see if it gets hot.
A 30VA transformer should run fairly cool, if it does then there is probably an issue with a component on that PCB.. Should it run hot you will need to replace the transformer.. Measure the voltages on the secondary and buy a Hammond or Antek that is close.
If you are going to dabble with tubes you need a good DMM, decent temperature controlled solder iron, and appropriate hand tools. Also you should read the safety and high voltage threads associated with this forum.
I'll be separating the transformer today to see if it gets hot all on it's own. But thought I'd share a video I made of it working with 2 bi-amped TA2024 amps.
Bi-Amping Class T Amplifier Tripath TA2024 - YouTube
p.s. Because I'm starting from scratch- is it possible to explain in baby talk how a transformer would connect to this board? If I bought a new transformer (labeled) as the stock one isn't... there's 0-6.3v and 230v connectors on board- with a new 115V 30VA (recommended) by seller or I'm open to suggestions- you see I've looked at several 30VA transformers and I'm still unsure about which power output I should get for a board marked 230v (sigh). I know once you know this stuff it's second hand, but I've only just learned the word 'filaments' :0
Best,
Xeta
Bi-Amping Class T Amplifier Tripath TA2024 - YouTube
p.s. Because I'm starting from scratch- is it possible to explain in baby talk
how a transformer would connect to this board? If I bought a new transformer (labeled) as the stock one isn't... there's 0-6.3v and 230v connectors on board- with a new 115V 30VA (recommended) by seller or I'm open to suggestions- you see I've looked at several 30VA transformers and I'm still unsure about which power output I should get for a board marked 230v (sigh). I know once you know this stuff it's second hand, but I've only just learned the word 'filaments' :0 Best,
Xeta
looks like you want a 230v secondary with 300v output, you might get away with 220. i wouldnt have thought youd need a 115v input on the board unless the switch was on the board too.
Edit
you would connect the 0-6v of the transformer into the 0-6v though by the looks of the board is it a 6-0-6 or 3-0-3? and youd plug the 230v of the secondary into the 230v part of the board. then connect the primary to the switch and mains input.
Edit
you would connect the 0-6v of the transformer into the 0-6v though by the looks of the board is it a 6-0-6 or 3-0-3? and youd plug the 230v of the secondary into the 230v part of the board. then connect the primary to the switch and mains input.
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So it's 110v in from outlet to (primary) and the secondary (230v) to the board?
I disconnected the supply and tested it for heat, on it's own. Sadly the transformer they included has no markings whatsoever. It may be better to start with a new one. It gets warm but not real 'hot' like before when connected to the board. Hmmm...
Board pics
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I disconnected the supply and tested it for heat, on it's own. Sadly the transformer they included has no markings whatsoever. It may be better to start with a new one. It gets warm but not real 'hot' like before when connected to the board. Hmmm...
Board pics
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Uploaded with ImageShack.us
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with no load i wouldnt have though a transformer would produce alot of heat if any, but i may be wrong, but yes you are right, 110v in from outlet to primary, then 230 secondary to board.
Transformer should be barely warm to the touch if there is no load on it.
I'd say you need to get a new transformer..
I've also noticed what appears to be a string of zener diodes connected by resistors back to the bridge rectifier, and am now wondering how much current they are running through those diodes.. Can you identify the values of some of those resistors and the zeners? Hand drawn schematic captured with a decent camera would work if you don't have access to a decent scanner..
I'd say you need to get a new transformer..
I've also noticed what appears to be a string of zener diodes connected by resistors back to the bridge rectifier, and am now wondering how much current they are running through those diodes.. Can you identify the values of some of those resistors and the zeners? Hand drawn schematic captured with a decent camera would work if you don't have access to a decent scanner..
Thanx razorrick1293. It is such a simple concept but it's still not easy finding that easy answer through google :0 That does help and makes sense.
kevinkr, with no load it was warm, luke warm? But nothing compared to when hooked up. I'll try and identify some of those buggers tomorrow.
Best to y'all,
Xeta
kevinkr, with no load it was warm, luke warm? But nothing compared to when hooked up. I'll try and identify some of those buggers tomorrow.
Best to y'all,
Xeta
That's encouraging, that transformer might be OK - just over loaded, and I'm guessing by a design issue.
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