Dynastatic speakers arrived but do not want to do anything before consulting with you

[planet10]

These speakers - or at least the mid/tweeter part - seems to be some sort of DIY electrostatic speaker.

More like a brand not far removed from the garage.

Caps date it to late 60s/70s.

Quite a few ESL + woofer. Qw hd B&W DM602 in the shop and much later i ran across some Jantzens.

There were many European consoles in the tube software tube voltages thaty uses SE ESL tweeters.

dave

 

[bazza31]

Thanks Galu,
The panels are 100% working after a 16hour charge, I've left them plugged in so it will be upto 40 hours at least. I will try later if no improvement how do I go about testing the spare panels

 

[AllenB]

Can you tell us the rating of the fuse which is used, and take a photo of it's position in the circuit?

 

[Galu]

how do I go about testing the spare panels

Each spare panel could be substituted in turn for the working panel in one of the speakers - assuming that could be done with the minimum of fuss.

 

[AllenB]

Not so fast, these things hold a charge and operate at high voltages.

 

[bazza31]

AllenB #45 and Galu, thank you, these are very dangerous. The spair panels I did not see any fuse. The plugs have 5amp fuses in and as in the pictures their are no fuses to see. If ther are readings to be checked I'd rather them be on the spair panels as they are safer than the ones plugged on

 

[Galu]

Here's some additional information on the Alex Shackman electrostatic panels, extracted and edited as before from this old thread:

H

Thread 'Can U identify these electrostatic units ?'

2012-11-08 1:40 pm

Hello
I was a speaker designer for Cambridge Audio in my youth, working on R50's and R40's and newer designs.
In my earlier student days (early 70's) my first purchased speakers were a pair of hybrid electrostatics that included the upper mid to high end units pictured here and sourced from a dealer located in North London suburbs (I think).

An externally hosted image should be here but it was not working when we last tested it.

[sorry, original picture location no longer available - see post #33 for new picture]
I quickly blew the bass units at a student party but the electrostatics were incorporated into...

• HiQual
• Replies: 33
• Forum: Planars & Exotics

See post #3 in the above thread for a PDF of a circuit diagram which may or may not correspond exactly with Bazza's speakers.

The panels employ a comparatively low HT voltage of around 400 V and have a very small stator gap. A cotton-like thread is used to space the membrane from the stators. The panels were designed in the era of low powered amplifiers and had the reputation of being hard to drive. The impedance dropped to 1 or 2 ohm at 20 kHz. The electrostatic panels are single ended and not push-pull.

Out of interest, Bazza, what are the dimensions of your panels? Are they 20 inches by 8 inches?

 

[stokessd]

Wow, those things are awful looking. Be very careful, and I wouldn't let them out of my sight when plugged in. Be super careful, it appears there are a lot of ways to shock/kill yourself with those. I can't believe someone sold these as a product.

Sheldon

 

[Galu]

More like a brand not far removed from the garage.

You are not far wrong! As stated in the old diyAudio thread mentioned above:

"Shackman worked in what appeared to be his front room (aka lounge) which was littered with speakers to do comparisons with."