Good Morning Jameson, I realized that I messaged Doc on an older thread. I just purchased one of the last SEX 3.0 units and am looking at pairing it with my other one, but setting them up as monoblocks. I didn't see a lot of information about these being used as monoblocks, but wanted to know if you have any advice. Thanks, Jason
SEX 3 Monoblocks
- Thread starter jstrano
- Start date
Good Morning Everyone, so last night I broke back into the build manual for the SEX 3.0. I have built 1 SEX 3.0 and also a Moreplay. The bug has bitten me again and I'd like to set up both of my SEX units into Monoblocks into the Moreplay. I have hundreds of hours on this system and love it and can't wait to improve. I've looked through some of the past posts and saw that Doc posted:
Basically you wire the two OT secondaries in series, float the free black binding post and retain the ground on the conjoined red and black post thus creating a grounded center tap for the secondary. Hmm, there may be some changes necessary on the headphone jack. Have to think about that a bit.
I've also seen comments from other folks that the headphone jack has to be unwired. I'm wondering if anyone has a schematic for running these units as monoblocks. I'm confident in my wiring/soldering. but don't want to mess anything up with an amazing system that I have. My kit was shipped yesterday, so I'm itching to get started! Thanks for any help.
Basically you wire the two OT secondaries in series, float the free black binding post and retain the ground on the conjoined red and black post thus creating a grounded center tap for the secondary. Hmm, there may be some changes necessary on the headphone jack. Have to think about that a bit.
I've also seen comments from other folks that the headphone jack has to be unwired. I'm wondering if anyone has a schematic for running these units as monoblocks. I'm confident in my wiring/soldering. but don't want to mess anything up with an amazing system that I have. My kit was shipped yesterday, so I'm itching to get started! Thanks for any help.
Yes, you'll have to forego the headphone wiring and put the output transformer secondaries in series (while wiring each for half of your intended load impedance). The first step for you to accomplish this would be to modify the amp for speaker only use, then test it, then you remove the ground reference for one channel from the speaker posts, then connect that floating speaker negative terminal to the other channel's speaker positive terminal (which puts the windings in series), then you use the two remaining binding posts as your output.
Paul, thank you so much for this info. Do you have a schematic that you could share? I believe that the S.E.X. started out as a monoblock in it's original configuration.
I do not have a schematic I can share. The original SEX amps were indeed monoblocks, but they used paralleled output tubes and one set of iron, which is not applicable to this exact situation.
Yes, we can look something like that over. It would/should only show the output transformers and their secondary wiring, which isn't particularly proprietary.
