I just found a pair of Realistic Mach One's (40-4024a) locally for $50. Thought what the hey, I'll try them out. Got them home, they don't sound too bad, but I know that they have 30 yr old caps inside that are probably all used up.
Just took the woofer off to look at the crossover.
It has three inductors (I'll probably leave those....)
two resistors - "2 (ohm symbol) K" and "8 (ohm symbol) K"
two bipolar capacitors - "50V 22(u symbol)F" and "50V (u symbol)F"
one yellow capacitor (two individual ones in a case) - "2.2 +/- 10 250V (then a K ?)"
My question, with the horns, is there timing issues related to the volt rating? I'm thinking that I'll replace the resistors with metal oxide ones and all three caps with Solen Fast caps (Metallized Polypropylene) rated at 250V, unless that can cause unwelcome issues.
Also another question, should cleaning the l-pads suffice, or are new ones needed?
Any ideas other ideas?
Just took the woofer off to look at the crossover.
It has three inductors (I'll probably leave those....)
two resistors - "2 (ohm symbol) K" and "8 (ohm symbol) K"
two bipolar capacitors - "50V 22(u symbol)F" and "50V (u symbol)F"
one yellow capacitor (two individual ones in a case) - "2.2 +/- 10 250V (then a K ?)"
My question, with the horns, is there timing issues related to the volt rating? I'm thinking that I'll replace the resistors with metal oxide ones and all three caps with Solen Fast caps (Metallized Polypropylene) rated at 250V, unless that can cause unwelcome issues.
Also another question, should cleaning the l-pads suffice, or are new ones needed?
Any ideas other ideas?
Inductors are probably fine, if they have small iron or ferrite cores they may cause a bit of distortion at higher powers.
The yellow cap may be a mylar cap if it is axial and a bit oval.
The volt rating affects nothing, 50 volts is enough for a 300W/8 ohm amp
Film caps can sometimes sound a bit brighter than 'lytics.
The L-pads may not need cleaning, I wouldn't mess with them unless they are scratchy.
The yellow cap may be a mylar cap if it is axial and a bit oval.
The volt rating affects nothing, 50 volts is enough for a 300W/8 ohm amp
Film caps can sometimes sound a bit brighter than 'lytics.
The L-pads may not need cleaning, I wouldn't mess with them unless they are scratchy.
you got a good deal on these. radio shack made good speakers back in the day. the mach ones keep their value and so do the newer mach two speakers. as long as the walnut vineer is in good shape you get one heck of a deal. You may want to test the caps to see i they are still working. a lot of people buy these then they dont end up using them often. the mach one speakers put out so much sound that it was hard for people to use them in apt buildings. people would get nocks on the door saying turn it down. I used to have the mach two's and wish i still had them. Now i own a house and could use them. I sold them even thoe they sounded great because the lady under me kept b*&ching to the leaseing office.
Replace with the same uf's, don't worry about voltage.
http://www.parts-express.com/dayton-metallized-capacitors.cfm
The white Mundorfs are well made and are modestly priced. I have used them in several projects so far with good results. Usually under 1% tolerance on my meter. You have piqued my curiosity now about changing out the electros in mine mainly as a conservative replacement/tune up than anything else; I'll add them to the next parts order.
There's this thing called a volume control.....
I use mine in an apartment.
My issue was I turned the volume control to high and was shaking things off the walls in other apartments. I know the match two's use a lamp as a fuse. I could watch it light up as the bass hit.
They were an xmas gift from my mom and dad. my mom still has two pair of these but she needs me to replace the foam on the woofers. I received my set after my mom got tired of me playing with her stereo. 
now as for the mach one speakers there are two versons of them. ones with rubber surrounds are older and bring in more money on ebay and the rubber seams to last forever, and then they came out with ones with the foam that falls apart in 20 years. the catalog numbers are almost the same. I think the one kind adds a letter behind it but i can't remember what is what.
Mine are the early rubber surround version and I am the second owner since new. The foam ones often do rot, but according to one of the excellent speaker repair firms near here, they have replacements.
re: the surrounds, I think (based on some internet research) that there might be three different iterations. 1 is the rubber surround (model 40-4024), the foam (40-4029) and a hybrid (?) foam that holds up very well (40-4024a)
re: the caps - Is it worth while getting better quality caps? I`m not sure if I have the extra cash-ola to spend on something more than the Solen fast caps I was looking at...
Also, I live in Canada. Is there a good place to get good cap's up here? The only site that I know of that has decent stuff is solen.ca.
re: the caps - Is it worth while getting better quality caps? I`m not sure if I have the extra cash-ola to spend on something more than the Solen fast caps I was looking at...
Also, I live in Canada. Is there a good place to get good cap's up here? The only site that I know of that has decent stuff is solen.ca.
I do have to say that I really enjoy the sound of these speakers, maybe it is just the sound of a horn, nice, rich full sound, albeit a little weaker on the bass than I would have thought it to be....maybe I need some more watts into them, although there are 60 watts of Sansui power feeding them....probably equivalent to 100 or more of todays watts.....
I just wish I could find another pair of them cheap. I don't want to pay the eBay prices. In my own opinion they sound better then a lot of speakers. they are great party speakers. you can make your house sound like the night club. Big bass, nice mids and nice highs, and they used a real crossover unlike a lot of other speakers. a lot of people think radio shack = junk. but back in the 70's threw the early 90's they made great sounding speakers as long as you bought the top of the line. around mid 90's their speakers started to go to H___. I flipped a pair of realistic optimus T200 tower speakers radio shack came out with in the late 70's. they had dual 10" woofers rated at 16 ohm each. ran in parallel. they cost more then the mach ones when new. there is a web page to look up old radio shack catalogs. http://www.radioshackcatalogs.com/ if you look at the catalogs you can see how the speakers started to go down hill. it started to get worse in 1994. in the early 90's they stared the mach 3 speakers only in 1992 and 1993. they are very rare to find. they are based off the mach one with the horn tweeter and horn midrange. you really don't see these coming up for sale. they didn't make them long. they made the mach two for many years and they made the mach one speakers for many years. they came out with a pro 4000 speaker in 1994 removing the tone control knobs and getting rid of the oil rubbed finish on the high end speakers. they made them cheaper to save money. if you look at the catalogs from them on the speakers kept getting smaller and smaller.
here is some more info the mach one speakers went for 20 to 25,000 Hz, the mach two speakers went from 25 to 40,000 Hz, and the mach three speakers wen from 30-20,000 Hz. the mach two speakers had the highest range of sound but if i remember right we cant hear what it goes up too.
the mach one speakers had the deepest bass but the mach twos had the best freq responce.
Last edited:
oh i forgot to say the mach ones came out new in 1976 and had a lifetime warranty. cat number 40-4024 and it's on page 46 http://www.radioshackcatalogs.com/catalogs/1976_small/ I wounder if you had the sales slips if they would still owner the warranty. In 1977 they came out with the 5 year warranty. i guess they changed their mind about offering a lifetime warranty.
Last edited:
The Solens will be fine as will the Mundorfs I mentioned which are similar price, at PCx anyway. You don't need to spend any more than these cost.
Have you never heard of Parts Connexion? Also in Canuckistan
http://www.partsconnexion.com/capacitor_film_mundorf_mkp.html
Bit of a memory lane trip with the catalogues. The Aussie ones were a bit different, but similar. I remember wanting a set when I was in high school and not being able to swing the $A299/spkr they sold for for years. Got my set about 2 years ago, and they came with the purchase receipt and a single line sales brochure on them.
They are quite good speakers. Not just for partying; I've been using mine as mains in the HT for a while, whilst I slowly build the new speakers. They do some stuff wrong, but they are fun to listen to.
Man did you just bring back some memories. around 1976 I was starting college and took a job as a tech at a regional repair shop at Radio Shack where I worked till about 1980. The Mach one speaker was pretty tough it took some pretty serious abuse to do damage . The T100 T200 was my favorite they delivered some pretty respectable sound . I actually have a few mach one woofers that I purchased as replacement parts back then which I have used in powered subs. so if you find some with bad horns don't overlook them for that use. Replacement surrounds are readily available and are quite simple to replace.
I sold the pair of T200's that I had on ebay last year for 200 dollars for the pair. they are quite rare to find. they were listed for some time before they sold. they were almost spotless but the one speaker had a ring stain in the walnut vineer. most likely could of been cleaned off with howards restore a finish. but it didn't look that bad.
I wouldn't pass them up with bad horns. if the cabnits are good you always see stupid people parting them out on eBay. mach ones go for less money being parted out on ebay. they would be better off to ether ship out the full speakers or sell them localy and do a buy it now price in their ebay stores and not worry about a quick sale. it took me about 2 weeks before my T200's sold I wasn't even sure what to ask for them so i did a buy it now price at 300 or best offer. I am guessing if the economy was better they may of sold for the 300. I couldn't find another pair that sold to get an idea of what to ask.
I bought them to flip since I have other speakers I like. They sounded so good I wasn't sure if i wanted to keep them and sell what I have or sell them. To tell the truth I wish i would of sold the infinity sm-152 speakers and kept the T200's
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.