Tubelab Simple SE In Parallel Mono Block?

[syyma]

Is there a way to config. a Simple SE to a parallel SE mono block? My single end fever still high. Any advise and recommend are more then welcome.

Best regards,

Sidney

[rknize]

I think it works pretty much the same as any other amp. Get an OPT with twice the power handling and half the input impedance or parallel the outputs using the appropriate secondary windings to achieve the required impedance for your speakers.

[syyma]

I'm thinking about to keep the big 8ohm 5k Edcor and order a Simple SE board from George and a PT from Edcor. The rest of the parts from my spare bin. But I just wouldn't figure out how to heck the board.
I read a post from George before about how to config. Simple SE to a parallel mono block somewhere but just can't find it.

Sidney

[Ty_Bower]

Originally Posted by syyma

I'm thinking about to keep the big 8ohm 5k Edcor

Not the greatest idea. I won't say it won't work, but you really want a different output transformer for parallel single ended. As Russ already mentioned, if a lone EL34 likes the 5K load, you want half that load for paralleled output tubes. You can give it a try, but it'll be like using a 10K transformer on a single tube. You'll get a lot less power out of it than you otherwise could. I thought the purpose here was to get more power. If you had started with a 3K output transformer, it would have worked out a little better.

If you really want to give it a go, read George's post here:
SSE left channel dead....

You're looking for the bit where he says:

Looking at the board from the top side with it oriented so that the "Tubelab Simple SE" printing is right side up, run a temporary jumper wire (solder a wire, or use a clip lead) from the left side of one coupling cap to the other (C11 and C21). It can be on either side of the board, but it must be on output side of the caps. This allows either driver circuit to feed both output circuits.

Now just disconnect one of your output transformers, and set it aside for the other monoblock. For the remaining output transformer, leave the B+ connection intact. Run a jumper between the plate connections so the transformer lead is tied to the plates of both output tubes.

When you say "Big Edcor", I'll assume you mean the 25 watt CXSE? It's got a screen tap. Have you already tried UL connection? That'll give you more power.

[syyma]

Ty_Bower,
Actually the SSE serve me well and always awesome to my ears.

Just to make the story short or may be a little bit crazy. I saw a pair of B&W Matrix 802 Serial 2 in more than good shape condition in a local pawn shop and the owner let me to bring my amp to try them on and the price just too good to pass up. I called the US B&W to verify the serial numbers and they said these pair are legitimate. So I armed with the SSE and Aikido 5687, with some classic rock albums and started to crank the Sultans of swing, Nothing else matters, Money, it sounds so good. When I played the Hotel California the kick drum sounds about two size smaller, I turned off the amp and flipped the UL and NFB switches and re-played the same tune still a size smaller compare with my ZaphAudio Waveguide TMM. I told the owner that my amp just not enough power to drive these pair of nice speaker and I can't bring them home for now. The owner of the pawn shop made a comment about he never had the experience of the music that sound so good.

Now I understand why I never feel short about my SSE because the WaveGuide TMM just 4ohm load and the xo with impedance compensation network but the Matrix 802 S2 just 8ohm loaded.

I think the bi-amps are much better approach for those not so easy to drive type of speakers.

Anyway, thank you so much for your input.

[tubelab.com]

Just to make the story short or may be a little bit crazy.

Nothing crazy, just normal interaction between the amp and the speakers.

An "8 ohm" speaker is not 8 ohms. It should be relatively close to 8 ohms when fed a 1 KHz sine wave at a relatively low power level. Even this isn't always true.

The impedance of the speaker varies with the frequency and power level of the applied signal.

It will also vary in real time. The impedance will be higher if an impulse (like a kick drum stomp) tries to push the cone further in the direction that it is already going, than it will be if the impulse tries to reverse the cone motion.

Many speakers are designed for use with modern solid state amplifiers that have a very low output impedance. A tube amp will have a higher output impedance than a solid state amp, and a single ended tube amp has a higher output impedance than a push pull amp. UL mode has the highest output impedance.

Many speakers have serious peaks in their impedance curves in the bass region, which make them a difficult match for some tube amps. I can not find the curves for these speakers, but their spec sheets call for amps in the 60 to 300 watt range.