And another new set of Poseidons on the bench!
Posted: Thu Aug 02, 2012 8:18 am..
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And another new set of Poseidons on the bench!
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Posted: Thu Aug 02, 2012 8:18 amPosted: Thu Aug 02, 2012 8:37 am..
Posted: Fri Aug 10, 2012 7:46 am..
Posted: Sat Aug 11, 2012 5:18 amSorry I didn't get here in a timely fashion, Wmacky.
Thanks for bringing up the differences between the B+ supply on the Poseidons and the Eiclones. The difference can probably be attributed to the Ike closely following the original Eico HF power supply. Since these units didn't have chokes like the Dynacos, and both units had puny 20uF can caps, the larger resistor and voltage drop was needed for the VA stage filtering. The detriment of that circuit was the lower B+, which hurts linearity.
But since the Eiclone supply is much better filtered, I think changing that changing R30 to a 100K resistor is a great idea. It makes the Ike better as the 12AX7 is just biased better.
Shannon
Thanks for bringing up the differences between the B+ supply on the Poseidons and the Eiclones. The difference can probably be attributed to the Ike closely following the original Eico HF power supply. Since these units didn't have chokes like the Dynacos, and both units had puny 20uF can caps, the larger resistor and voltage drop was needed for the VA stage filtering. The detriment of that circuit was the lower B+, which hurts linearity.
But since the Eiclone supply is much better filtered, I think changing that changing R30 to a 100K resistor is a great idea. It makes the Ike better as the 12AX7 is just biased better.
Shannon
Posted: Sat Aug 11, 2012 3:22 pmNo Worries Shannon.
BTW, I deleted my questions only because I was going to post them on another forum, and didn't want to leave a trail of the same questions cross posted across multiple forums!
Thanks for the response.
If I understand correctly, You recommend keeping the listed 330V B+, and the 121K plate load value from the posieden schematic, rather than using the IKe values, even when going with a custom PS that could go either way.
Is that correct? This pertains to using Poseiden boards only...
BTW, I deleted my questions only because I was going to post them on another forum, and didn't want to leave a trail of the same questions cross posted across multiple forums!
Thanks for the response.
If I understand correctly, You recommend keeping the listed 330V B+, and the 121K plate load value from the posieden schematic, rather than using the IKe values, even when going with a custom PS that could go either way.
Is that correct? This pertains to using Poseiden boards only...
Posted: Sat Aug 11, 2012 3:39 pmWmacky wrote:If I understand correctly, You recommend keeping the listed 330V B+, and the 121K plate load value from the posieden schematic, rather than using the IKe values, even when going with a custom PS that could go either way.
Is that correct? This pertains to using Poseiden boards only...
Yes, go ahead and stick with the standard values from the Poseidon schematic. Beef up the stock supply with more capacitance in your custom PS. Use a CL90 inrush to protect against soaring B+ before the tubes warm up. Definitely make sure you have bleeders in there, too.
Shannon