Old Monitor 5's

schwarcw

I picked up a cherry pair of Monitor 5's today for $60. No batteries in the camera so I'll post tomorrow. These are real beauties. Except, they have the dreaded SL2000's (I think). I'd like to plug in a pair of Peerless tweeters that I have in my spare parts stash. Anyone see a problem with that? The owner's manual states these are 4 ohm nominal. The Polk site states the later models have an 8 ohm nominal load. I would prefer to hook these babies to my vintage Scott LK72 with the 7591 tube compliment. The Scott has multiple speaker terminals for the speaker connections. I plan to use the 4 ohm terminals, any nay sayers?

ESavinon

The sl-2000 are a little wider than the peerless tweeters.

schwarcw

Sounds like that you have done this tweeter swap out. What were your impressions? Any crossover tweeks? I didn't see a crossover schematic for the original 5's just the Model 2 with the SL2500.

Carl

ESavinon

I don't have the monitor 5. I do have the 5jr+
I have a few pair of speakers with the sl-2000 as well as the peerless tweeters.
They're of different sizes. I've only changed the sl-2000 with the rdo-194.
Highly recommended if you want to get rid of the sl-2000.

schwarcw

Hi Ed,

I do have a couple of RDO 194's and I also have a pair of Peerless. Any recommendations what I should use. That's why I'd be interested to see the original crossover schematic for the Monitor 5's.

Carl

ESavinon

The rdo's are a drop in replacement.
I prefer the sound of the peerless over the rdo's.
They sound very similar.

heiney9

schwarcw wrote: »

Hi Ed,

I do have a couple of RDO 194's and I also have a pair of Peerless. Any recommendations what I should use. That's why I'd be interested to see the original crossover schematic for the Monitor 5's.

Carl

Carl,

Here you go. Use the RD0's you'll thank me later . There is a schematic on here (3) to be exact if you can't find it I have it on my hard drive.

http://www.polkaudio.com/forums/showthread.php?t=51420&highlight=5b%2A

H9

P.s. also keep in mind if your's are fused rather than a poly switch use a 2.7 ohm resistor not the 2.0 like in the schematic. Where are you finding the sl2500 version?

heiney9

The "original" M5 with the peerless has a different x-over board because it has (2) resistors rather than one. Not sure if the sl2000 x-over can be modified to use the peerless easily.

schwarcw

Brock, the only schematic I could find was the schematic in the "sticky" that Doro posted. It does have fuses in the rear. I think you did a cap mod if I recall? I'll post some pictures later.

heiney9

schwarcw wrote: »

Brock, the only schematic I could find was the schematic in the "sticky" that Doro posted. It does have fuses in the rear. I think you did a cap mod if I recall? I'll post some pictures later.

Yes I did, I put the link in post #7. IMO, it might be hard to "convert" the x-over to use peerless tweets. Go with the RD0's and the cap(s) of your choice. Just beware the fused Monitors use a 2.7 ohm resistor rather than 2.0 ohm which the poly switch equipt Monitors use. The p/s must add a little bit of resistance.

H9

NJPOLKER

I have a pair of SDA2a's that had SL-2000's and tried my spare Peerless tweeters with great results. I had updated the x-overs with matching values to the stock caps and resistors awhile back and used RDO's till I thought maybe I should try the Peerless.
The Peerless were not a perfect size match but worked out ok. What could it hurt to try it out? I think you should try it and let us know what you think. Unless there is an issue where you can damage something and I am sure one of the guys here will let us know if there is.
Drew

heiney9

NJPOLKER wrote: »

I have a pair of SDA2a's that had SL-2000's and tried my spare Peerless tweeters with great results. I had updated the x-overs with matching values to the stock caps and resistors awhile back and used RDO's till I thought maybe I should try the Peerless.
The Peerless were not a perfect size match but worked out ok. What could it hurt to try it out? I think you should try it and let us know what you think. Unless there is an issue where you can damage something and I am sure one of the guys here will let us know if there is.
Drew

Certainly can't hurt to try it. I was just pointing out that the x-over components are different for Peerless equipt Polk's. The RD0's are the correct electrical equivalent. I personally don't like swapping things in and out that are significantly different than the original design.

Some people like trial and error; I do for certain things. In this case the x-overs are different enough I thought I'd mention it.

I wouldn't modify the cabinet opening (if one has to) in order to "try" something.

YMMV

H9

NJPOLKER

I should probably look at the components,caps and resistors, in the 2a and Monitor 10 x-overs and see for myself what the differences are. Or maybe I'll just leave well enough alone,naaa thats no fun.
Drew

fredv

I also have a Monitor 5B that I wanted to upgrade. My estimate of a pair of RD0's, Solen caps, and resistors was around $160 out of pocket. Since I could use the Solens caps for my other projects if it didn't work out, I replaced the caps and resistors of the xover. Well, it did improve the dynamic and the definition, but it wasn't to the point I would say that I should have done earlier. This kind of validate what others said, replacing the sl2000 has more impact than upgrading the parts. BTW, I am using an Eico ST40 all tube integrated and the 4 ohm tap. The M5B is 6ohm, this will present a higher load the tubes but less distortion.

I considered whether I should order the RD0's - around $104 shipped. Then I was wondering what could I get for around $160, i.e instead of buying the parts to upgrade, what can I but for that money? So, I held onto the RD0's purchase until latel, I came across a pair of GR-Research A/V-1, Danny Richie's entry level kit at $175. I always want to try Danny's kit, but my significant half will never allow me to do an woodwork. I feel this is one stone to kill 2 birds opportunity. These A/V-1's are not the latest kit which has a newer silk dome tweeter and redesigned xover. So, this pair is not the best A/V-1 but do have the full Sonicap upgrade.

Thanks to USPS, I didn't receive the second speaker until this Tuesday and had to repair the copper foil inductors as the copper foil were broken off the xover board!! They were compared to the M5B in the same set up in the last 2 days, and I switched 2 sets of speakers back and forth a couple times. The AV/1 stays there since then. Even though the M5B's are supposed to be more efficient (only 86 db for the A/V-1), the A/V presents much better dynamics and bass. I don't have the M5B's specs, but it probably is in the 40-ish range, where the A/V-1 is only down to 55hz. What stands out is how well the little 2-way blends the high and the low. My gut feeling is that the M5B can be close to the A/V-1 with the RD0's but still will come up short, but I am not going to spend the $$ for a pair of RD0's to try :-)

fredv

Forgot to mention, the Eico ST-40 also uses 7591 output tubes, 20 wpc. I suggest to try both the 8ohm and 4 ohm taps with the M5B. Just use the one that sounds better on the LK72. Either tap will do just fine with the amp.

schwarcw

Thanks for the advice Fred. Lot's of good ideas to ponder. I need to pull the crossover out and see what's in there.

fredv

If I remember correctly, the LK72 also has a pretty good phono stage. If you happen to have vinyl gears around, give it a try!!!

schwarcw

The LK72 has a great phono stage! I do have a table in the mix!

Check out the photo's of the original Monitor 5's:







Sorry for the quality of the photo's:(, My camera batteries died!

gcstokes1

HI
New here, but confident that the minds here can help me along.
I have a pair of M5B that seemed to be working fine when I got them. Now one tweeter is out. I have done a basic check of connections. I must say that the circuit type board is a little confusing to me. Obviously I can only check what is on the surface.
How do I tell what kind of tweeter it is to look for a replacement? Is there something that I can do to troubleshoot the problem? Are these tweeters interchangable with other models so that I can look at other options for replacement?
Should I upgrade both tweeters if there is a better one that fits?
Quite a few q's eh?
Any and all advice is very much appreciated.
Thanks
Glen

ben62670

Welcome to club Polk. You can take your good tweeter, and move it to the bad speakers cabinet. This will tell you if the tweeter is bad, or if there is another problem. The RDO replacements are well worth the upgrade. Mention you are a club Polk member to get the discount price.
Enjoy
Ben

fredv

Welcome, Glen.
Do your M5B have fuse near the binding posts? If so, check to see the are blown or not.
Next, you can take swap the 2 tweeters and see the problem follow. If so, you have a blown tweeter. If it is the tweeter, you can either purchase a new pair from Polk (you don't want mix new and old tweeters) or buy a used one. In case you want to go with the used route, post you tweeter model, it is likely a SL2000, but it is better to be sure.

Good luck!!

Ricardo

The M5B could have a Peerless tweeter..so the RDO not necessarily will fit.

How do those tweeters look? Silverish cone, or black? Do the leads go straight righ/left like in the pictures above, or at a 45 degree angle?

gcstokes1

Thanks to all for the quick responses!!
I will do the swap between cabs and see what happens. (Why didn't I think of that??).
Ricardo, I don't see a picture above you referred to. I will look at the wiring and color and report.
Hopefully I can enjoy these soon. I used to have a pair of M5 (not 5A), and liked them. Thanks again for your help.
G

gcstokes1

HI
Feeling very goofy here. Mine are 5A, not 5b.
I have checked the fuses and they are fine. When I tested and found that the tweeter was out, the woofer was working, so I assume that the problem is with the tweeter. From the specs that I read, the tweeter is a SL2000. I have taken some pics and attached them here.
Tell me more about the RDO, and or other upgrades. Where do I find the RDO so I can look at pricing. Ben mentioned that if I mention Club Polk, that I cn get a discount. Where is that seller? I have read that there are SL2500, and SL3000. are these options and do they have advantages?
I would like to try and make these the best that they can be. Their size vs sound fit right into n office system that I am designing.
Should I re-cap?
Thanks to all, and forgive my goof on the model. After all, under my name it does say "Polkie".
G

ben62670

You have the peerless tweeter. Regarded by many the best tweeter for old Polk's. I would try to find another peerless. Yes you should do the caps, and resistors. Did you test the tweeter with a multi meter yet? Polk carries the RDO tweeter, but it is larger than the peerless so you would have to do some cab modding. I don't recommend that.
Ben

gcstokes1

Thanks Ben
I am happy to know that I have the better tweeter already.
Is there only one model of Peerless? Any sources for the Peerless that are more reliable than others?
What am I testing for, (and how) on the multi meter?
I would rather not modify the cabinet, and with the peerless, I only have to replace one driver. On the caps and resistors, Dayton good enough? I have re-capped most of my older speakers, with good results. I have never done resistors, any advice on the brand?
Too many questions?
I will stop here.
Thanks
G

ben62670

Questions are good. I love the Dayton's. Sonicaps are the choice caps here by most. Mills are good for the resistors. As for the tweeter any Polk Peerless will work. Hopefully you can find one with the hole. Keep looking here, and also Ebay. It may take a while, but it would be worth the hunt. Where are you located?
Ben

gcstokes1

I am just north of Denver CO.
I like the dayton price.
All of the Peerless that I have seen are round, not the same shape as mine. Does the # on the back give any clues as to model #? What is the hole that you refer to?
The mills resistors in PE are 2.5 ohms, and 12w, as you can see in the pictures, mine are 2.7 and 5w. I think that the 2.7/2.5 are within tolerances. What about the watts?
Glen

ben62670

Go with the 12w 2.5r, and you will be fine. I have had the Sonicaps, Solen's, Jantzen's, and Dayton's here. The Sonicaps are great, but for me the Dayton's are more forgiving with bad recordings than the Sonicaps, and the Dayton's still retain detail, and accuracy. I do also want to try clarity caps too.
Ben

gcstokes1

Ben
Just a thought. Is there a way to tell if the problem with these tweeters is the resistors or the caps? If I am going to replace them anyway, maybe I could replace them and get the tweeter working again.
Can I test the caps and resistors wtih a multi meter. If so, how?
Thanks
G

ben62670

Test the tweeters with the multi meter. Both tweeters should be close in resistance.
Ben