Whatever happened to DCM's Steve Eberbach? - Page 35

You may also want to keep you eye on Craigslist, both local and state wide. Every once in a while, you'll come across someone selling an old dilapidated pair that you can cannibilize for parts.

Alright!! I have finally read through the entire thread, and all I have to say is WOW! Very impressive work Jamie, and thanks to everyone for all of the great information. I am still so new to the understanding of how speakers are put together generally, let alone the intricacies of DCM speakers, so please forgive me if i ask some dumb questions.
Here they go:
How do I determine the cause of my non-functioning tweeters? Is it likely the tweeters themselves that need replacing, or could it be bad wiring? The speakers themselves have been in my garage for many years, not being used. It is an insulated, attached garage, but living near Chicago means the garage can get in the 20 degrees in the winter and the 90 degrees in the summer. Forgive me, I didn't know what I had!! Other than this factor, they have never been jostled, dropped, or abused in any way. Just thought maybe if I could find the cause, I could find the fix.
So obviously, I do not understand anything about internal crossovers or magnetic voice coils, etc. so, I am not sure if I'd also need to be looking at repairing or replacing these for any reason.
What about the mid range woofers? Since I'll be looking to either fix/replace the tweeters, should I also look into the others driver as well? I was able to do some google searching and found some relatively cheap tweeters on PartsExpress that have been said to fit the tf600 tweeters perfectly.
I really appreciate any help and guidance that can be offered. Just curious now as to how to get started with this! Thanks so much!

So, I pulled the connection terminal to see if it was a matter of just a blown fuse. I don't have a testing meter, so I just eyeballed the lamp and it appears to be intact on both speakers. I attached a pic, not sure if there is anything else that looks alarming. If it isn't the lamp fuse, I suppose it must be the tweeters themselves?
What is your opinion on the Goldwood gt-302/s1/2" Mylar dome tweeter shielded from parts express as replacements?

Um, also - I do not EVER remember seeing this bulb fuse lit. I'm not sure if it is supposed to light up when pushed, or if it is always supposed to be on...but I never saw it light up ever.

It should start to light up as more juice is put into it because that is what protects the circuit. Just go to Harbor Freight and get a cheap multimeter and check for continuity across the fuse.

Another update:
I took out all of the tweeters. I tested all of them from the center position. Ironically, the one in front and the one on the right rear side of each speaker were bad. I presume this of course. My rationale: The one on the left rear side works, but only when placed in front/center. It will not work on its own from the rear. The other tweets will not work from the rear with the when the working tweeters are placed in the front/center. Unless there is something I'm missing, it sounds like I just need to replace those rear tweets. Any problem with running one of the original rear tweets as the center? Should I replace all of them?
Thanks for being patient with an amateur.

As my esteemed colleague flyng_fool stated " get a cheap multi-meter and check for continuity across the fuse".

But I would guess if from what you just mention that the bulb is good because all the tweeters run through it. In other words, if it where blown, you wouldn't hear any of them working in any position.

The two rear tweeters run in series with a single resistor. They pick up just after the bulb but before the time delay circuit. The 1.8 ohm resister is just before the first rear tweeter which is then connect to the second rear tweeter. Don't confuse it to the second 1.8 ohm resister which is also right after the bulb but goes to the time delay circuit for the front tweeter.

If you look at your photo of the crossover, the brown lead should be the positive for the rear tweeter with the blue being the negative lead. The 1.8 ohm resistor for the rear tweeter is the one under the bulb closest to the spade connectors.

Because they all run in series, if either of the tweeters or the resistor is bad, or if you have a bad connection, nothing will work.

So, if the front tweeter position is the only one that works, it means that there is a problem in the rear circuit. Use your newly purchased multi-meter and set it to check for continuity.

The easiest way to check the wiring and resistor (I would assume they're both good) is to remove both rear tweeters and tie the leads together (remember which leads go to the positive and negative) . Remove the blue ground wire from the circuit board. Check for continuity by touching the leads to the end of the blue wire and to the end of the light bulb closest to the spade connectors. If it's open, you have a bad connect or wire somewhere or bad resistor. If that's good you should just need to replace the bad tweeters. Ebay is your best place to find them. DCM used that tweeter in a lot of their later products. I you can't find any used DCM tweeters, use the good ones that you have in the front because the dampening circuit is designed for the modified DCM tweeters. The rear ones would not be as critical.

Here's a copy of the schematic, for reference. R3 is the resistor for the rear tweeters.





P.S. Also, change out the electrolytic cap on each board.
Edited by Jamie Hauser - 1/28/13 at 12:04pm

Wow. Nobody's referred to me as an esteemed colleague before. I must be moving up in the world!

I'm a big DCM fanboy and have read this thread in its entirety and have enjoyed it thoroughly. There's been some great information here. And I'm now motivated to get my hands dirty and do some extra work on my 5 pair of DCM speakers. Yep, 5 pair and growing.

I am currently doing a top to bottom refurb on two pair of DCM speakers and have a couple of questions concerning the crossovers of the DCM Timewindow 1a's (I think they are 1a's) and Timeframe 500's.

Each pair of crossovers contain two 47uF electrolytic capacitors per crossover. The other capacitors are film foil or something else, but they aren't electrolytic for sure. I haven't measured their values yet, but they don't tend to stray like electrolytic caps.

1. Are the signals sent through capacitors with that high of a value typically sent to ground or to cut out high frequencies to woofers?
2. If so, would it matter (and if so how much?) if I replace them with other 47uF electrolytic caps or should I use metalized polypropylene caps for better tone?

If the 47uF caps are used as a shunt to ground, obviously I'd much rather use some decent electrolytic caps because the much larger size of the metalized polypropylene caps presents a problem for both pair of crossovers as they wouldn't be a neat fit. If the 47uF caps are in the signal path, then I have some major headaches.

One pair of crossovers is for a DCM Timewindow 1a where the point to point crossovers on a stick are mounted onto the oak bottom base of the speaker inside the cabinet. The crossovers could be removed from the base and hot glued onto a piece of plywood (ala poor man's Bob Crites Klipsch crossovers) with the plywood mounted along a flat side wall of the speaker cabinet. It would require a lot of extra work. I can do this. However, if it isn't going to really matter (shunt to ground) I'd rather not bother with it all.

The other pair of crossovers are for DCM Timeframe 500's where the crossovers are built onto an epoxy board and then mounted inside the speaker cabinet. I would have to run speaker wire from the original 47uF cap insertion points on the epoxy board to where the metalized polypropylene caps would be hot glued onto the cabinet. It can be done, but it would be kind of messy. Again, if it's a shunt to ground I'd rather not bother.

Money isn't a real concern. Doing things right is more important. It's more of a question of how right.

Thank you very much!

I have another question about older DCM speakers. This is concerning a pair of Timewindows.

I have a pair of Timewindows that don't have a designation on them. They don't state TW 1 or TW 1a or anything on the label by the speaker terminals.

My gut tells me they may be 1a's as each cabinet as the lighter stained oak caps, two Vifa D19TD05-08 fabric dome tweeters, two made in Taiwan 5 ohm woofers, tweeter screens with diffraction material, woofer diffraction material and both cabinets are covered with a brown fabric sock. These speakers have a single bass port on the front of the speaker cabinet near the bottom.

As memory serves, the original Timewindows used Philips drivers, had no diffraction materials, had very dark stained tops and bottoms and were covered with a thin foam material that was secured by two clamps on the back of the speakers. These speakers also had 2 bass ports near the bottom in the front of the speaker, one on the left side and one on the right.

Does anyone know for certain which Timewindows I have?

EDIT: New information added in bold.
Edited by Doctor Morbius - 1/28/13 at 4:56pm

Correct me if I'm wrong but I could have sworn they came in both light AND dark caps.

I have a pair of Timewindow 3's also and they are much larger in both height and volume than the ones in question.

Timewindow 1a's definitely had the lighter stained oak caps. The original Timewindows had much darker oak caps. The oak caps on mine are the same as the TW 1a's.

I'm just wondering if I have TW 1a's that aren't labeled as such or if they are a transitional speaker between the originals and the TW 1a.

If that's the case, I'm unaware of it. I'd always though 1 = dark and 1a = light.

Pretty much everything after a certain point had the lighter stained oak caps, then later on there were some models produced with black painted caps. I would assume that was done for cost savings.
Edited by Doctor Morbius - 1/28/13 at 4:47pm

I had a member ask about wanting to make replacement tops for their TimeWindow Sevens that are completely missing. I decided to post the working drawing in this thread in case someone else would like to do the same. I had to piece the drawing together from four scans, hence the odd look.

The tops and bases are both there. The top (being the smaller) is overlaid on the base. The 5/8" and 9/16" holes are just for the base and the four recessed slots are for the Mod-eze clips #1763 found here: http://www.mod-eez.com/Specifications_Page_1.htm , are for the tops only. The profiles for the tops and base are shown in the top corners.



Edited by Jamie Hauser - 1/28/13 at 7:13pm

The electrolytic caps are not in the signal path, just use a good quality replacement. This is the best that I have found as of yet, It's specs are better than the original ones.

http://www.erseaudio.com/s.nl/it.A/id.4594/.f?sc=15&category=833

The other caps are Mylar (polyester) film caps. The one used as the high pass filter should be the one with a value of 6.8 uF. You could replace that one if you like with a polypropylene like this one.

http://www.erseaudio.com/Products/PulseX250v/MPX25-03-6-80

Replacing the electrolytic caps are a must, the film should be fine.

Check this thread for more information, it's been covered quite a bit here.

Thank you for getting back with me. I truly appreciate it. My biggest concern was the 47uF caps. I will get the ones you linked above when they are back in stock. And I'll probably get the 6.8 uF high pass filter cap also.

Thanks again!
Edited by Doctor Morbius - 1/29/13 at 8:42am

Wow!!!
Thanks for all of the great information!!
I am happy to report that after following your advice, I have successfully diagnosed the problem as bad tweeters. I replaced the two rear tweets on each speaker with Goldwood GT-302 Mylar dome shielded tweeters from Parts Express. They fit perfectly and sound amazing. I moved the only two working DCM tweets from the rear to the front on each speaker as suggested. The end result is that everything is now working as spectacular as I remember!!
I can appreciate going back and listening to certain favorite songs, and really hearing them the way I remember. Makes me fall in love with the music all over again. Brings back great joy and memories. Now I have to think hard about where the heck I'm gonna put these bad boys! They are BIG.

Not to sound like a total idiot, but what exactly is the electrolytic cap? Is this something that is of great concern?

Thanks again to all for all of your help - Jamie, you THE BEST!!!

The non-polarized electrolytic caps in your crossovers will look like this ...




These kinds of capacitors stray from their original value with age.

What to do with the original tweeters? Toss them? Keep them? Sell them? They do not work.

Your welcome.

The only electrolytic capacitor that the TF600 crossover has is the dark blue, can shaped one (C5 on the schematic). It's part of the dampening circuit for the front firing tweeter. Here's a good replacement, you'll need two to do both crossovers.

http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-15-0-PB

toss em.

I just purchased a pair of TW3 that are in need of some TLC. I've been reading through all of the posts here over the last few days and have learned a lot. I've had a pair of the Timeframe 1000's since the late 80's that I've listened to them almost daily since I got them. But lately I've had a hankering to get my hands on some Time Windows and came across a pair of 3's that I picked up last week.

After listening to the TW3's for a week now I have some observations as to how they compare to the TF 1000's that I have. The TW3's are certainly warmer and have a more detailed sound stage. The TW3's have a deeper and tighter bass than the TF 1000's. But I have noticed the TF 1000's are much more dynamic that the TW3's that I just got. The TF 1000's are brighter, have much more detail - especially in the high's - and are generally livelier.

I realize that different speakers have different characteristics and tendencies but comparing the two I get the sense that the TW3 are a bit flat. After reading through the posts in this thread I'm willing to do some work to overhaul the cross overs. I've read Jamie's post #883 where he gives links to caps that can be used to replace the existing ones and I have some questions.

1. Would it be possible to use a film cap with the same values as the electrolytic caps? For example something like this http://www.mouser.com/ProductDetail/Kemet/MMK375476J100R03L4TRAY/?qs=sGAEpiMZZMsh%252b1woXyUXj3lo7E554VG1jlRaRjKgGtU%3d. If it was possible to use the film caps what would be the advantages and disadvantages?

2. I was reading Jamie's post #852 where he was discussing the caps he was using on the TW7 clones. He says that Steve Eberback recommended replacing the mylar caps with polypropelyne ones. Would this be a good thing to do on the TW3's as well? If so does anybody know of good replacements?

3. Does anyone have any information or suggestions on setting the calibration pots on the bottom of the TW3's? It is possible that the previous owners messed around with them and they are set incorrectly and are affecting their performance.

4. Does anybody have a good source for black sock material to recover these speakers. I'm not talking about the headliner material that is attached to the speaker cabinet, but rather the black fabric on the outside of the speaker.

5. Lastly, the labels around the dispersion controls on the back of the speaker are curled up, and one also has a crease in it as if it was folded. Does anybody have any suggestions on how to make them flat again?

I greatly appreciate any feed back that I can get.

Newbie here, love this thread. Looking for suggestions, I have TF600's for my front speaker and 2 CX27's for my rear. I have a Denon avr2113ci receiver, I need a decent center speaker and a sub to complete my Home Theater. Any suggestions?

I would go with a Soundscape center followed by a CX-17 and then the CX center in that order. Which reminds me, I have a spare CX-17 if anyone wants to throw a few sheckels in my direction.

Here's one for Jamie (or anyone else that may know.) Have you heard of the DCM Time Window Soundscape speakers? The black high gloss base and tops remind me of the Time Window 7s. Any thoughts or opinions? Some available here.

I have an Atlantic Technology 453c mated to my TF600's and it is a very close timbre match.

You may also want to look at this thread: http://www.avsforum.com/t/1419776/help-me-find-matching-center-channel-for-vintage-dcm-speakers

In post # 10, I explain the differences between the choices.

While I never had the opportunity to listen to the Time Window Soundscape speakers, I have had read a good review: http://www.audio-ideas.com/reviews/dcm.html and also had read the manual: http://www.dcmspeakers.com/manuals/TimeWindowSurrScape.pdf .

I did talk to Steve E. about them when a nice pair come up on Ebay a few years back. While he liked them very much (he's currently using a set), he said the only downside is that they are not as accurate as the other TimeWindows speakers. If you read the review and manual you can see that while they do look like regular TW's, their intent and design are quite different. They can do things that the other TW's can't, but I believe at the cost of some accuracy that is the TimeWindow's fame.

And while they do look like the TW7, they're about 8" shorter and 17 lb lighter.

Thanks Jamie. I pretty much found the same info about an hour ago. Someone is selling a pair here in town and was playing around with the idea of buying and refurbishing them. Then I just got a call an half-hour ago from someone willing to sell his TW3s for a song. If this works out, I'll have four TW3s and two CX-17s for a 7:1.