Simple P-P OPT choice

musical noise · 1st September 2012, 01:20 AM

I came across a couple of Edcor p-p opt's that are 12k:6 Ohms (single secondary) that I would like to use for the Simple P-P. I know that the design is optimized for a 7.8k plate to plate primary load, so I was wondering what effect if any, the higher primary load would have besides less power. Do you guys think it'll be ok in this application? My speakers are a nominal 8 Ohm load but they do dip to 4 Ohms at around 200Hz.

rmyauck · 4th September 2012, 08:11 PM

25W ones?
Should work with the nice side effect of less distortion, with the tradeoff as you know of less power. The higher primary is better for cathode bias anyway. Heathkit used around 10-11K on their EL84 amps OPT's, on the popular AA-151, and earlier mono blocks. They were rated @ 14W/CH.

Randy

musical noise · 5th September 2012, 02:25 AM

Randy, thanks for responding. Yes these are 25 watters. I had also guessed the power with these trafos to fall somewhere in the 13-15 watt range and that's ok. Having less distortion is not that bad of a trade-off.

rmyauck · 03:31 AM

Your welcome! I bet they will sound really nice with that board/amp! 6V6 's would be usually spec'd with 10-12K , but you would have to wire off the board. B+ would have to be adjusted too! The Heathkit W5M amps also used a really high primary also of close to 10K with 6L6's and many say that's why they sound so nice. Normally 6-7K was used.

Regards!

Randy

rmyauck · 5th September 2012, 03:59 AM

Actually the Heathkit W5M used KT-66's, but 6L6's are commonly used and are supposed to sound great.

Randy

1st September 2012, 01:20 AM	#1
musical noise diyAudio Member Join Date: Sep 2004 Location: ---	Simple P-P OPT choice I came across a couple of Edcor p-p opt's that are 12k:6 Ohms (single secondary) that I would like to use for the Simple P-P. I know that the design is optimized for a 7.8k plate to plate primary load, so I was wondering what effect if any, the higher primary load would have besides less power. Do you guys think it'll be ok in this application? My speakers are a nominal 8 Ohm load but they do dip to 4 Ohms at around 200Hz.

5th September 2012, 03:22 AM	#4
rmyauck diyAudio Member Join Date: Apr 2009	Your welcome! I bet they will sound really nice with that board/amp! 6V6 's would be usually spec'd with 10-12K , but you would have to wire off the board. B+ would have to be adjusted too! The Heathkit W5M amps also used a really high primary also of close to 10K with 6L6's and many say that's why they sound so nice. Normally 6-7K was used. Regards! Randy Last edited by rmyauck; 5th September 2012 at 03:31 AM.

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4th September 2012, 08:11 PM	#2
rmyauck diyAudio Member Join Date: Apr 2009	25W ones? Should work with the nice side effect of less distortion, with the tradeoff as you know of less power. The higher primary is better for cathode bias anyway. Heathkit used around 10-11K on their EL84 amps OPT's, on the popular AA-151, and earlier mono blocks. They were rated @ 14W/CH. Randy

5th September 2012, 02:25 AM	#3
musical noise diyAudio Member Join Date: Sep 2004 Location: ---	Randy, thanks for responding. Yes these are 25 watters. I had also guessed the power with these trafos to fall somewhere in the 13-15 watt range and that's ok. Having less distortion is not that bad of a trade-off.

5th September 2012, 03:59 AM	#5
rmyauck diyAudio Member Join Date: Apr 2009	Actually the Heathkit W5M used KT-66's, but 6L6's are commonly used and are supposed to sound great. Randy