My hybrid ESLs are finished.

[chinsettawong]

Hi!

I spent the past few months learning, making, taking apart, and remaking. Finally, I am proud to say that my first Hybrid ESLs are done.

Here are the details:

Stator Size: 120 x 30 cm.
Spacer Thickness: 3 mm.
Diaphragm Type: 6 microns Mylar.
Diaphragm Coatiing Material: My own PVA glue formula.
Bias Voltage: 7.2 KV.
Step Up Transformer Ratio: 1:88.









Thanks a lot to everybody who has contributed to this forum for all the wonderful information.

Wachara C.

[c2cthomas]

Very Nice!! Wish it was mine - but then I'm a sucker for OB and AMT's.

[hifipaul]

hello WACHARA Well done with the ELS speakers.In the uk I had the Quad ESL57's for years great sound.I bought the ESL 63'S When they came out had them for 2 weeks and sold them the sound was greatly inferior.I am living in pattaya perhaps could hear yours somtime. Paul

[CharlieM]

Awesome dude!

That much bias voltage should give really good output (SPL). Just curious, what's your diaphragm/stator spacing?

Great job!

[SY]

Is that a 1:88 voltage step-up ratio??? Impressive that you managed that without severe frequency response problems. What's the % open area of the stator material you used?

Nice job!

[chinsettawong]

Originally Posted by hifipaul

hello WACHARA Well done with the ELS speakers.In the uk I had the Quad ESL57's for years great sound.I bought the ESL 63'S When they came out had them for 2 weeks and sold them the sound was greatly inferior.I am living in pattaya perhaps could hear yours somtime. Paul

Hi Paul,

It's nice to hear from somebody in Thailand. If you have a chance to come to Mahachai, Samutsakorn, do let me know.

Wachara C.

[chinsettawong]

Originally Posted by CharlieM

Awesome dude!

That much bias voltage should give really good output (SPL). Just curious, what's your diaphragm/stator spacing?

Great job!

Hi CharlieM,

The diaphragm/stator spacing is equal to the spacer thickness, which is 3 mm.

Wachara C.

[chinsettawong]

Originally Posted by SY

Is that a 1:88 voltage step-up ratio??? Impressive that you managed that without severe frequency response problems. What's the % open area of the stator material you used?

Nice job!

Hi SY,

Why is it that I will run into the frequency response problem? The transformers are custom wound especially for ESL. I'm not sure what the % open area is, but the hole size is 6 mm. If I have to guess, I would say that the open area is around 60%.

Wachara C.

[SY]

Originally Posted by chinsettawong

Hi SY,

Why is it that I will run into the frequency response problem?

That high of a ratio generally means high capacitance and leakage inductance. IME, anything over 30 or 40 to 1 was problematic, but I'm not an expert on transformers... Who wound them for you?

[chinsettawong]

Originally Posted by SY

That high of a ratio generally means high capacitance and leakage inductance. IME, anything over 30 or 40 to 1 was problematic, but I'm not an expert on transformers... Who wound them for you?

The transformers are wound by a local audio transformer maker. They kindly sponsored me on this project. I know about the possible problems of the leakage inductance and high capacitance. But, these transformers are very well made, and I don't have high frequencies roll off problems. I'll try to make some measurements later.

Wachara C.