Double Bass Wherefore art thou, Walter Woods?

[jsherm]

After 30 years of utter reliability, my Walter Woods MI-225 is occasionally reluctant to boot up. It makes the usual popping sounds, but it will hang for many seconds before the final pop and full power. Last week at a rehearsal, to my absolute horror, it just popped and popped and would not boot. Tried it again a half hour later and it worked, thankfully. For a week and a half I've tried daily to contact Walter at his (760) 219-4122 phone number. Crickets. I leave messages daily and can't get a response. I've found an amp repair place (SF area) that says they can work on WW amps, but they would need to get the parts from Walter. Is Walter still alive??! Does anyone have any idea how I can reach him? Best amp ever. But I can't take the chance of getting to the gig and having it not boot up.

 

[MrSidecar]

I have found this number as his land line: (760)-772-7952

I have several times during the past two weeks tried to call the man, to no avail. However, in february 2015, another TBer had the same and Walter eventually returned the call by caller-id. Guess you/we have to be patient.

However, not to discourage you, but I faintly remember (from some thread around here) that THAT precise model MI-225-8 is the only one that can't really be repaired due to parts not being available anymore. I might be wrong though, try the search function and maybe something turns up. Good luck!

Best
Sidecar

 

[Ric Vice]

After 30 years of utter reliability, my Walter Woods MI-225 is occasionally reluctant to boot up. It makes the usual popping sounds, but it will hang for many seconds before the final pop and full power. Last week at a rehearsal, to my absolute horror, it just popped and popped and would not boot. Tried it again a half hour later and it worked, thankfully. For a week and a half I've tried daily to contact Walter at his (760) 219-4122 phone number. Crickets. I leave messages daily and can't get a response. I've found an amp repair place (SF area) that says they can work on WW amps, but they would need to get the parts from Walter. Is Walter still alive??! Does anyone have any idea how I can reach him? Best amp ever. But I can't take the chance of getting to the gig and having it not boot up.

J Sherm,
Walter is likely out on one of his vacations, it gets really hot in Palm Desert, CA, as I understand it. Even with the appropriate parts, I'd be skeptical about having someone other than Walter, work on one of his amps. Walter himself has said that he can no longer
repair the older MI-225-8 that has two mono 100 watt power amps, ganged together. I believe it's the only Woods MI amp, that has two sets of cooling vents in the top of the amp. Sorry I can't be more helpful.

Ric

 

[robgrow]

Walter has told me in recent times that the MI 225 is in fact repairable and parts are available. The real problem as I see it is getting in touch with the man. If you do, you don't know what kind of mood he will be in. He can be very generous, or tell you that he is no longer supporting the old amps, or charge a very large fee, or anything in between.

If the power amp or power supply is indeed dead and Walter can't be reached, or wants a lot of money to repair or says he is no longer repairing this model, I have successfully transplanted an ICEpower power module (which has a built-in SMPS) in an old MI 100 with a dead PS. Most of the tonal character that we love about these old amps comes from the preamp, which probably still works just fine or is easily repairable if it doesn't.

Sorry I cannot offer to do this for anyone else, but it can be done.

 

[MrSidecar]

I have successfully transplanted an ICEpower power module (which has a built-in SMPS) in an old MI 100 with a dead PS. Most of the tonal character that we love about these old amps comes from the preamp ...

Rob,

that sounds like an interesting project- could you share your experience and how-to and stuff? I'd love to see some pictures as well.. I just recently bought an MI100-8 that is working fine (apart from one preamp channel that has the buzzes), but I have thought about something in that direction in case something goes wrong...

Best
Sidecar

 

[robgrow]

Rob,

that sounds like an interesting project- could you share your experience and how-to and stuff? I'd love to see some pictures as well.. I just recently bought an MI100-8 that is working fine (apart from one preamp channel that has the buzzes), but I have thought about something in that direction in case something goes wrong...

Best
Sidecar

I sold the old MI 100, so I no longer have it. I'm on to the next project.

Replacing a dead power board on an old WW amp is pretty straightforward if you have some experience in that area. All the engineering and hard work has already been done by ICEpower. There is a designer's manual available from ICEpower: Invalid Link Removed Read this and follow the directions carefully. Wire routing, etc. is important. The WW preamp works on +/- 15VDC, as I remember, and the ICEpower module supplies +/- 25VDC, so you have to regulate that down, which is very simple to do and is covered in the designer's manual. Also a balanced signal is required to drive the ICE BTL module. These things are all available on the internet for reasonable prices, so you don't have to build anything. It's not quite a ready to assemble kit, but it's not too far from it. I would only recommend this project to someone who has some experience with high-quality audio electronics, good practice and safety however. It's not a beginner's project.

For reference, here is a schematic for a commercial amplifier which uses an ICEpower 50ASX2: [Invalid or Expired Link Removed]

 

[Jazz Ad]

How old is Walter Woods by now?
I thought is technophobia/introversion was funny 10 years ago, nowadays I just find it plain ridicoulous.
Of course I get that he doesn't need much exposition but still, a bit of presence and support for his brand wouldn't hurt.

 

[MrSidecar]

I sold the old MI 100, so I no longer have it. I'm on to the next project.

Replacing a dead power board on an old WW amp is pretty straightforward if you have some experience in that area. All the engineering and hard work has already been done by ICEpower. There is a designer's manual available from ICEpower: Invalid Link Removed Read this and follow the directions carefully. Wire routing, etc. is important. The WW preamp works on +/- 15VDC, as I remember, and the ICEpower module supplies +/- 25VDC, so you have to regulate that down, which is very simple to do and is covered in the designer's manual. Also a balanced signal is required to drive the ICE BTL module. These things are all available on the internet for reasonable prices, so you don't have to build anything. It's not quite a ready to assemble kit, but it's not too far from it. I would only recommend this project to someone who has some experience with high-quality audio electronics and good practice and safety however. It's not a beginner's project.

Rob,

I have looked into what has do be taken care of when hooking a preamp to an ICEPower module, because I was thinking in the same direction with another amp I once had. I certainly think this would be doable for me, once the need came about (at least with the Woods, the other amp in question was a little less straightforward, because the preamp required single-rail voltage, and some parts of the design were a little unusual and not easy to transfer to a new power amp board). For the time being, the only hiccup my MI100-8 has is in one preamp channel (channel 2) , and that seems to be something that either I can cure myself, or in any case I know a good repairman that can take care of that.

The bit with the balanced signal is, btw, an answer to a question I asked you (was it you? i think so) in another thread, concerning the feeding of a signal into the 125ASX2. When taking an UNbalanced preamp signal, one has to provide a 180 degrees phase different signal on one input in order for BTL mode to work. But with a balanced signal, that is not necessary.

best
Sidecar

 

[MrSidecar]

How old is Walter Woods by now?
I thought is technophobia/introversion was funny 10 years ago, nowadays I just find it plain ridicoulous.
Of course I get that he doesn't need much exposition but still, a bit of presence and support for his brand wouldn't hurt.

In another thread, somebody posted amplifier manuals for a later model, and part of that document was a "partial buyers list". More like a who's who for bass players, I mean, LOTS of seriously legendary and famous players. Exposition on the web is nothing Walter Woods has any need for (You know that dude from the cover of the first Fatboy Slim record, wearing at shirt saying"I'm number one, so why try harder?").

best
sidecar

 

[robgrow]

Rob,

I have looked into what has do be taken care of when hooking a preamp to an ICEPower module, because I was thinking in the same direction with another amp I once had. I certainly think this would be doable for me, once the need came about (at least with the Woods, the other amp in question was a little less straightforward, because the preamp required single-rail voltage, and some parts of the design were a little unusual and not easy to transfer to a new power amp board). For the time being, the only hiccup my MI100-8 has is in one preamp channel (channel 2) , and that seems to be something that either I can cure myself, or in any case I know a good repairman that can take care of that.

The bit with the balanced signal is, btw, an answer to a question I asked you (was it you? i think so) in another thread, concerning the feeding of a signal into the 125ASX2. When taking an UNbalanced preamp signal, one has to provide a 180 degrees phase different signal on one input in order for BTL mode to work. But with a balanced signal, that is not necessary.

best
Sidecar

re: "single-rail voltage" the ICEpower module will supply DC voltage up to +25 volts. For single rail, just use the positive connection on the auxiliary power plug (P103). Just make the current draw is not over 200ma (which it probably is not).

re: 'balanced signal" there may some confusion in terminology here. My background is in professional audio where balanced lines are used extensively and singled ended is less common. I used an audio transformer to derive the necessary input configuration in one project, and an IC op amp based balanced line driver in another. Both methods worked just fine.

 

[MrSidecar]

Thank you very much, Rob...

re: "single-rail voltage" the ICEpower module will supply DC voltage up to +25 volts. Just use the positive connection on the auxiliary power plug (P103). Just make the current draw is not over 200ma (which it probably is not).

Sure, but the preamp was running on +40volts :-( .

Never mind, that's a while back and not something I still need or want to do to that amplifier (which is gone again as well).

Best
Sidecar