rolotube
Head-Fier
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- Feb 27, 2009
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Quote:
The transformers may be designed to run fairly warm, but I question how long they will last at the highish temp you describe. Here in Oz we have no choice, it has to be the 370 DAX (240V mains) & this seems to be a different beast altogether. I'm running an EZ81, choke PS, 6H30 & ECC99's with regal's & amphead's mods & it never gets much above lukewarm. You can certainly leave your hand on it, even after several hours. I tend to listen at a more or less constant volume (fairly low) & haven't noticed any variation in transformer temp. All voltages are within 10% of "book" values.
Shinkoh tantalums & Blackgates arrive tomorrow from PcX. Plan is to replace all amp resistors & use Blackgates at C2 (amp) & C3 (PS). I know this is probably overkill but tinkering is fun & may even yield some subtle changes or improvements.
Originally Posted by funch /img/forum/go_quote.gif My 270DAX also gets hot enough that I can only leave my hand on it for a couple of seconds. It's also mounted on top of the case. I've done the Regal and Amphead mods, and use a separate heater tranny for the EZ81. I'm running 6H30's on the input, and ECC99's on the output. The other day, I fired it up with no signal and let it run for a few minutes. Then I checked the voltages on the amp boards. All were very close except at the junction of C2, R2, and V1 which should read 3V. Mine was at 6.4V. Then I connected my source and listened at a moderate volume level for most of a CD. The tranny was still barely warm. Then I turned up the volume one step. By the end of the CD, the tranny was hot again. |
The transformers may be designed to run fairly warm, but I question how long they will last at the highish temp you describe. Here in Oz we have no choice, it has to be the 370 DAX (240V mains) & this seems to be a different beast altogether. I'm running an EZ81, choke PS, 6H30 & ECC99's with regal's & amphead's mods & it never gets much above lukewarm. You can certainly leave your hand on it, even after several hours. I tend to listen at a more or less constant volume (fairly low) & haven't noticed any variation in transformer temp. All voltages are within 10% of "book" values.
Shinkoh tantalums & Blackgates arrive tomorrow from PcX. Plan is to replace all amp resistors & use Blackgates at C2 (amp) & C3 (PS). I know this is probably overkill but tinkering is fun & may even yield some subtle changes or improvements.