Double Bass Walter Woods repair

[crd]

I emailed the folks in Chicago, never heard back…

I'm not sure how keen they are on shipping etc. It can't hurt to call. It seemed like the shop in Berlin was game but shipping to Europe and back is definitely a PITA.

I am slowly putting my pennies away to hopefully get a M700 to pair with a Felix which seems to be a similar rig. But it's a lot of cash. And I will never get a chance to a/b those two rigs which is irritating but the way it is. Right now I am using the Felix into the WW which is overkill and glorious.

 

[Keyser Soze]

I emailed the guy in Berlin -- Christoph Nass (Audio Repair Berlin) -- asking about repairing Walter Woods amps. Here's his detailed response;

Hallo, yes, you are welcome.
Your amp: I would ask for some photos:

Outside: Top, Front, Bottom, Rear, Serial Number (embossed on heatsink main fin, becomes visible after removal of the top lid

Gut shots: Main PCB component side 4...6 photos 1 Total, 3...5 detail. Main PCB Copper side: 2..4 photos, 1 Total, 1..3 detail

Later, If I accept:

To be exempt from duties on my side and to ease/lift duties on your side I will need to make up a Pro Forma Invoice stating value and intended processing of your amp (a preview is in attachment).

For that I will need

your full name, business address and shipping address

1 photo of your amp's front view

1 photo of the amp's exact model (silkscreened on bottom lid)

1 photo of serial No. (becomes visible after removing of the top lid, embossed on heatsink spine)

Once I get that information I will complete that Pro-Forma-Invoice and send it to you via e-Mail.

Please print that out on paper and sign it.

Then scan or photograph it, copy that file for you

Send the scan/photo file to me via e-Mail,

I will print that out to use it on arrival at german customs.


Put that original Pro-Forma Invoice into a clear envelope marked: "To be opened by customs" and affix that outside the parcel, together with your customs declaration.

Mark the item as "Amp, defective, for repair", value 10 USD.

Lets get that paperwork correct, because customs will try to collect duties on both sides, adding shipping cost to the value and whatnot.

Any import duties levied on me I will have to add to your invoice.

Repair may be successful only if 2 parts are still working:

1. There is one unmarked PWM modulator IC (WW has usually ground off all markings to keep his design secret)

that is still terra incognita and can not be replaced as long as its specs are unknown.

If that IC is broken there is still a chance of etching the molding resin off and miscroscope the silicon die to find any markings.

I did not have to do that with any repair before, but such research has to be performed once, and it may be your amp.

2. The handwound power transformer which is undocumented as well so far.

I am close to its specs and if defective, I will be at its specs once I have to unwind it.

I did not have to do that with any repair before, but it may be your amp which might be the first and hopefully I may be able to successfully rewind it

If everything fails and repair comes out unsuccessful I may be buying your amp for parts.

Bitte unbedingt 30 min vor beabsichtigter Anlieferung / Abholung +49-172-3004001 anrufen, (SMS werden unter Umständen verzögert zugestellt) !
Please do call +49-172-3004001 in any case 30 min before intended bring-in / pick-up (Messages might be delayed in transmission) !

Besten Dank für den Auftrag und viel Spaß beim Musizieren !

Beste Grüße, Grüezi, Servus, Kind regards, Adios, Au revoir, Arrivederci, До свидания, A Viszontlátásra, Farvel !

audio-repair-berlin.de
Dipl-Ing. Christoph Naß
Simplonstrasse 14
D-10245 Berlin-Friedrichshain
GERMANY
Tel.: +49-172-3004001
Website:
www.audio-repair-berlin.de
-----------------------------------------------

 

[CryingBass]

The guy in Chicago ( Amp Works? ) got back to me. I used the "contact us" on their website.

He said he "got lucky" to figure that the one out. I think he would be willing to try another repair, but I get the impression that they have maybe done only that one WW amp, are admittedly not "experts" on Walter's particular designs ( who is?! ), and I am guessing parts / schematics would be another challenge.

But I am Chicago-based and would give them a chance if mine ever needs repairs. Hopefully never!

Good luck you guys.

 

[toddg63]

My man Christoph is thorough, right?

Hallo, yes, you are welcome.
Your amp: I would ask for some photos:

Outside: Top, Front, Bottom, Rear, Serial Number (embossed on heatsink main fin, becomes visible after removal of the top lid

Gut shots: Main PCB component side 4...6 photos 1 Total, 3...5 detail. Main PCB Copper side: 2..4 photos, 1 Total, 1..3 detail

Later, If I accept:

To be exempt from duties on my side and to ease/lift duties on your side I will need to make up a Pro Forma Invoice stating value and intended processing of your amp (a preview is in attachment).

For that I will need

your full name, business address and shipping address

1 photo of your amp's front view

1 photo of the amp's exact model (silkscreened on bottom lid)

1 photo of serial No. (becomes visible after removing of the top lid, embossed on heatsink spine)

Once I get that information I will complete that Pro-Forma-Invoice and send it to you via e-Mail.

Please print that out on paper and sign it.

Then scan or photograph it, copy that file for you

Send the scan/photo file to me via e-Mail,

I will print that out to use it on arrival at german customs.


Put that original Pro-Forma Invoice into a clear envelope marked: "To be opened by customs" and affix that outside the parcel, together with your customs declaration.

Mark the item as "Amp, defective, for repair", value 10 USD.

Lets get that paperwork correct, because customs will try to collect duties on both sides, adding shipping cost to the value and whatnot.

Any import duties levied on me I will have to add to your invoice.

Repair may be successful only if 2 parts are still working:

1. There is one unmarked PWM modulator IC (WW has usually ground off all markings to keep his design secret)

that is still terra incognita and can not be replaced as long as its specs are unknown.

If that IC is broken there is still a chance of etching the molding resin off and miscroscope the silicon die to find any markings.

I did not have to do that with any repair before, but such research has to be performed once, and it may be your amp.

2. The handwound power transformer which is undocumented as well so far.

I am close to its specs and if defective, I will be at its specs once I have to unwind it.

I did not have to do that with any repair before, but it may be your amp which might be the first and hopefully I may be able to successfully rewind it

If everything fails and repair comes out unsuccessful I may be buying your amp for parts.

Bitte unbedingt 30 min vor beabsichtigter Anlieferung / Abholung +49-172-3004001 anrufen, (SMS werden unter Umständen verzögert zugestellt) !
Please do call +49-172-3004001 in any case 30 min before intended bring-in / pick-up (Messages might be delayed in transmission) !

Besten Dank für den Auftrag und viel Spaß beim Musizieren !

Beste Grüße, Grüezi, Servus, Kind regards, Adios, Au revoir, Arrivederci, До свидания, A Viszontlátásra, Farvel !

audio-repair-berlin.de
Dipl-Ing. Christoph Naß
Simplonstrasse 14
D-10245 Berlin-Friedrichshain
GERMANY
Tel.: +49-172-3004001
Website:
www.audio-repair-berlin.de
-----------------------------------------------[/QUOTE]