Quad ESL57s - panel rebuilds....

[Ivor]

This is a useful site for quad speaker info ...

http://www.quadesl.org/index.html

james

Thanks for that James... there's always something new to learn abpout ESLs. Or maybe that's just me.

[Fran]

ah, they're only 1N4007s - I have a couple of hunnerd of them here....

I'll have to investigate further....


Fran

[Dowser]

Yep - bits I order were;

Order Code Qty Description Mftr. & Part No.
----------------------------------------------------------------------------
9565051 40 DIODE, STANDARD, 1A, 1000V MULTICOMP - 1N4007.
9527257 20 CAPACITOR, 10NF, 2000V MURATA - DEBF33D103ZA3B
1612066 2 GAS DISCHARGE SURGE SUPPRESSOR LITTELFUSE - CG3-1.5L
1357969 10 RESISTOR, 2W 5% 2M2 MULTICOMP - MGRF2WJ0225AA9
489803 10 RESISTOR, 2W 5% 330K MULTICOMP - MCF 2W 330K.

Comes to €36 with VAT at today's prices, all in stock. Note the Gas Discharge Suppressors are for protection against arcing - these are the suggested items instead of the Quad method of diodes which are supposed to affect sound quality negatively according to a few on the internet.

I didn't fit them this time around, it meant removing the output transformers and I just couldn't be arsed - next time :)

If you find somewhere to get pure beeswax let me know - or if you'd order me some too I'd appreciate it. I also have a spare set you can have to rebuild first if you like? Although they are the original ones from my ESLs (someone on PFM bought OTA replacements and sent me their old ones FOC!), with correct date stamps for my serial numbers, so would quite like them back one day (unless yours happen to have same date stamp on the beeswax holders as mine!).

Thing to note when replacing is that; there were two types of EHT cct - early used 16 diodes, late used 8. 16 diode versions are more reliable (and the IN4007s are cheaper), so accepted wisdom is to replace 8 diode types with 16 diodes (just series 2 up across existing holes - if you look at piccies in my PFM thread you can see how I did it, as I had one early and one late type board). It is also important to ensure there are no sharp edges when you are finished; this means you should cut legs to length and then solder, rather than solder and then cut legs (mistake I made first time, easily fixed by resoldering with extra solder on pads).

Cheers and good luck! Fitting rebuilt units will (should) improve you bass and mid-range no end!

Richard

Edit to add: Feck, formatting lost - email me if you want it legible!

[Ciaran]

From Bronze casting experience I was pretty sure you'd get beeswax from RPM Supplies, and yes, it is listed on their website. (Wow! They have a website now!) They used to be on Dorset Street, but now they've moved to Ballymount Industrial Estate near Tallaght.

[Fran]

The likes of Lenihans in capel st always had beewax blocks.... most furntiure places will have it and definitely you can get it online from the major suppliers.

I know I have half a block of it around here somewhere.


Why did they use beewax and not ordinary paraffin wax I wonder?

Fran

ps. thanks for the parts list. The quads were sounding so good last night I'm actually loathe to touch them! If you're free sometime you should call down. I'd be interested to see what you would think of them compared to freshly done ones.

[Fran]

Just read through your threads on PFM Dowser - great to have those pics.


I just need to wind myself up to do the EHT rebuild. My problem is that they sound good already!! I'd need to get some of those caps too - and might as well do the resistors too.

I wonder if you could repair the damaged dustcover/panel. I was wondering as I read the posts if you could just add another bit of the conductive film just around the damaged area and then tape over the hole in the dustcover. That might just get you sorted wrt to the levels issue side to side and also the arcing. I know Dereks sounded incredible with new dustcovers.

Some of those lads on DIYaudio might well have a small amount of the fluid they could sell you for small $$. FWIW, 3M do a tape that you can get in the bigger stationery shops. It looks and works just like sellotape, but it won't yellow or go brittle (I have some I used on an old map here at least 15 years ago and its still OK). I bought some a while back for making a tape belt for my TT so it is still available.

Would be good to get you down here to have a listen to my quads - would be good iot have the opinion of someone with new EHTs to see if I need to do anything at all.... how are you fixed I wonder?


Fran

[Dowser]

I'm sure we could work something out Fran - I could probably load mine into the back of the car for a direct comparison :) It would help me too - I have a feeling the bass panel that has the damage is causing that unit to be a little bass light in comparison to the other.

Best for me is a weekday evening - how does that work for you? And where are you based?

I considered just replacing the dust covers (an easy task in comparison to a full panel rebuild), and am busy reading up on repairs I can do to the stators themselves with the dust covers off. However, if there is a hole in the conductive sheet between the stators then a full rebuild is the only way I guess. Part of me wants to try it, part of me is scared :)

I've tracked down a pair in bad condition that someone is willing to donate to allow me to try a panel rebuild without ripping mine apart...but they are in the United States. Anyone know any good US based shipping companies with rates lower than UPS/DHL (a service like PharosParcel would be ideal - I shipped my current pair from UK to here for only £40!).

Alternatively, does anyone have any faulty ESL57 panels they want to sell me? If I can get 1 treble and 1 bass, then I can do a staged rebuild.

Cheers, Richard

[Fran]

Weekday evenings work very well for me too - usually except thurs night.

If you can load them up, great.... I have a couple of different amps we can try them with....


I'm near Naas, about 6 miles from J10 off the M7

Fran

[Dowser]

Sounds good - let me check with mission control and I'll PM you - either next week or week after I guess.

What sources have you got? Vinyl and CD?

Richard

[Fran]

Grand...


vinyl & CD and valve and SS amplification