More speakers

rcag_ils · « **on:** 13 Mar 2009, 08:38 pm »

Wooohooooo, my new used Sonographe SL-21 speakers have arrived. They are ported, time aligned design. The first 10 minutes of auditioning with the cold Ultra 550, I am very impressed by it's image, I mean the image's just pouring out at me. Their real oak veneer matches my Sonographe SG-3 turntable.

I don't know a whole lot about these speakers, other than from a copy of old ad that I have from 1987. There aren't much information that I can find on the internet. If anyone knows more about these speakers, please enlighten me.

rcag_ils · « **Reply #1 on:** 14 Mar 2009, 05:39 pm »

How do I post pictures again, it didn't work.

JerryM · « **Reply #2 on:** 14 Mar 2009, 05:53 pm »

Are these what you wanted to post?

Very nice!

Have fun,
Jerry

rcag_ils · « **Reply #3 on:** 14 Mar 2009, 05:59 pm »

Yeah, how did you do it? I tried to copy the pics, but I couldn't paste it.

JerryM · « **Reply #4 on:** 14 Mar 2009, 06:11 pm »

Quote from: rcag_ils on 14 Mar 2009, 05:59 pm

Yeah, how did you do it? I tried to copy the pics, but I couldn't paste it.

You have a PM.

rcag_ils · « **Reply #5 on:** 14 Mar 2009, 06:14 pm »

Let's see if it works

JerryM · « **Reply #6 on:** 14 Mar 2009, 06:15 pm »

rcag_ils · « **Reply #7 on:** 14 Mar 2009, 06:38 pm »

According to my 1988 Audio annual equipment directory, the SL-21 had two versions of optional sub-woofers, the SX1000 and the SX500. The SX1000 had two 10" woofer in the cabinet, and the SX500 had one 10" woofer.

The SX1000 and the SX500 also had an active crossover, the SX1. The SX1 was available pre-configured for the SL-21/SW1000 system, or may be special ordered with custom designed crossover freq. and slopes of your choice.

Since conrad johnson didn't sell a lot of these, so the chances of getting the optional sub-woofers are slim to none. Boy, don't I want to get a hold of them.

Sigh......the good old days.

Listens2tubes · « **Reply #8 on:** 15 Mar 2009, 02:51 pm »

Interesting

They look like a good DIY project.

bummrush · « **Reply #9 on:** 15 Mar 2009, 02:58 pm »

Very nice looking speakers!How far away do you sit?Do they image really good so you dont need any toe in?Nice set up.

rcag_ils · « **Reply #10 on:** 15 Mar 2009, 06:11 pm »

The position of the speakers shown in the pictures are for show only. I placed them about 2 feet from the back wall, and where I sit is about 5 to 6 feet from them.

I have a fairly good size listening room, the surrounding walls are pretty much bare, other than some lp racks, and unused audio equipment (plenty of those), there's really nothing for acoustical taming, but I am working on it.

I experimented these little monitor size speakers in different positions, and I've found that toe-in will soften up the sound a bit, and very pleasent to listen to, very nice image, facing them straight will make the image more forward.

The low end goes surprisingly low on these , it's rated down to 57Hz, but sound lower, crossover at 1.5K, so it has nice midrange. I have to say though, even the low is there, but not at very high level. Maybe that was the reason why there were two optional subwoofers available for these at the time.

I have two individual 8" passive subwoofers from my Cambridge Soundworks Ensembles set that I purchase years ago, the satellites speakers for this set are long gone. I may connect these subwoofers to them and see what it'll sound like. I've heard that mix and match passive sub with other monitors could be tricky, an active sub with different slopes and freq would be ideal for this purpose.

Yeah, they look kind of like DIY pieces, don't they? But the cabinets are very solid and inert, I tap around the cabinet, and there's no trace of hollow cabinet resonant feedback.

rcag_ils · « **Reply #11 on:** 31 Mar 2009, 07:23 pm »

Spring's here, it'll be my spring project in the garage, to install the Pat Tobin mod, said to outperform many other modern speakers in the thousands dollar range. Oh, these are the Bozak 313, the smallest Bozak that Rudy made at the time. They have a 12" woofer, alumium midrange and tweeters.

These sound kind of muddy now, they'll be my spring project #2, to replace the caps. Sorry, there'll be no fancy new cabinets on these, I'd rather keep them "vintage"

Recently finished project this past winter, rewired the arm, and installed it on a custom armboard, aligned the cartridge and all.

Gotta have something "made in Japan" in my inventory. An outstanding reel to reel.

That's all folks, for now.

Wayner · « **Reply #12 on:** 31 Mar 2009, 09:43 pm »

I see you have a Rega R200 tonearm. How is the anti-skating belt on that?

I also see the lovely Dynaco A25XLs. Have you been inside yet? Often, the woofer terminals come apart and need some minor rebuilding to isolate the flex wire from the frame. This can damage the amp if both terminals are shorting to the cast frame. The good news is the frame is painted and does isolate the problem a bit, but if you haven't been inside, this is one thing I'd check...and maybe you already have.

The pair I had rebuilt had cabinets in fairly ding'd up condition (corner trauma) so that is why I had new cabinets made. I do have another pair in their natural un-altered state. Nice stuff at any rate.

What's the make on the RR?

Wayner

Listens2tubes · « **Reply #13 on:** 31 Mar 2009, 11:10 pm »

Looks like your plate is full of fun projects.

Great to see and also inspiring.

rcag_ils · « **Reply #14 on:** 1 Apr 2009, 02:06 am »

Quote

I see you have a Rega R200 tonearm. How is the anti-skating belt on that?

I also see the lovely Dynaco A25XLs. Have you been inside yet? Often, the woofer terminals come apart and need some minor rebuilding to isolate the flex wire from the frame. This can damage the amp if both terminals are shorting to the cast frame. The good news is the frame is painted and does isolate the problem a bit, but if you haven't been inside, this is one thing I'd check...and maybe you already have.

The pair I had rebuilt had cabinets in fairly ding'd up condition (corner trauma) so that is why I had new cabinets made. I do have another pair in their natural un-altered state. Nice stuff at any rate.

What's the make on the RR?

I think the anti-skate on my R200 still works. I turned the anti skate knob from one end to another slowly (not all the way, of course), and I felt various resistance, I also adjusted it on the fly while playing a record, and I heard audible differences, so I've concluded that it works, I don't really want to mess with it too much.

I have not been inside the A25XL yet, and I do remember you mentioned about the woofer terminals, so I will use the care of a brain surgeon when I work on it. Wonder if you took any picture of these terminals, so I know what I'll be up against? The cabinets are in decent shape, the guy who sold it to me didn't play them much, so basically these speakers were transferred from his closet to my closet.

The reel to reel is a Pioneer RT-909, I just replaced the belt four days ago, and it is in wonderful cosmetic and operational condition. I also have a Pioneer RT-1011, you can see part of it in the bottom right corner of the first pic. The RT-909 is all micro processor control, you can go from fast forward to play without using the stop function first. I like these reel to reel, they built like tanks.

The Bozak speakers were ahead of it's time in the 50's and 60's, there has been a cult following lately, so I'll rebuild the crossovers, and see what they sound like. Bozak made their own speaker drivers to spec in the factory, I've heard that their 12" woofer had the best response of all woofers made.

avahifi · « **Reply #15 on:** 1 Apr 2009, 09:25 pm »

I would love to hear those Bozaks in good working order again today with modern equipment driving them.

Years ago we rebuilt the crossovers in a set of big ones owned by the father of one of my assistants. We simply replaced all the electrolytic capacitors in the crossovers (which had badly aged and become very resistive at high frequencies) with modern film capacitors of the identical values, matching them channel to channel. The results were pretty impressive, it was like taking a wet blanket off of the speakers.

If you must mess with replacing capacitors in an audio component, an old but good loudspeaker is a good place to start. Just be sure you keep a 100V minimum rating on all the capacitors, and use non-microphonic, non-inductive wound non-polar film types, and match them channel to channel. Industrial grade Panasonic EF and E series capacitors are a good place to start, we doubt if "audiophile" grade capacitors will make a further worth the cost effort. You need a capacitor meter more than you need expensive capacitors.

Regards,

Frank Van Alstine

Wayner · « **Reply #16 on:** 1 Apr 2009, 09:28 pm »

I do have some pictures of how I repaired the terminals. I'll post them when I can find them.....
Wayner

Wayner · « **Reply #17 on:** 1 Apr 2009, 09:50 pm »

Here you go. You have to dis-assmble the flex wire from the broken wire terminals. Be wery, wery careful, huh,huh. I got the grommets from Ace Hardware. If you can't find any. I can get them. The grommets measure 1/4" OD in the groove and about 1/8 ID. the outer lip is about 3/8.

The speaker terminals are from Rat Shack. install the metal shaft thru the grommet and put the all the stuff together. Make sure you put lock-tite on the screw threads or the whole thing will vibrate apart. I'd like to find some better connectors, but no luck, yet.

You may have noticed that I use those plastic wall hangers and put them into the mounting holes for the woofer so I can set it face down and not touch the surround, which is a great idea. Also makes working on the speaker real easy.

Wayner

rcag_ils · « **Reply #18 on:** 1 Apr 2009, 11:09 pm »

Quote

I would love to hear those Bozaks in good working order again today with modern equipment driving them.

Years ago we rebuilt the crossovers in a set of big ones owned by the father of one of my assistants. We simply replaced all the electrolytic capacitors in the crossovers (which had badly aged and become very resistive at high frequencies) with modern film capacitors of the identical values, matching them channel to channel. The results were pretty impressive, it was like taking a wet blanket off of the speakers.

If you must mess with replacing capacitors in an audio component, an old but good loudspeaker is a good place to start. Just be sure you keep a 100V minimum rating on all the capacitors, and use non-microphonic, non-inductive wound non-polar film types, and match them channel to channel. Industrial grade Panasonic EF and E series capacitors are a good place to start, we doubt if "audiophile" grade capacitors will make a further worth the cost effort. You need a capacitor meter more than you need expensive capacitors.

Regards,

Frank Van Alstine

Frank,

Thanks for the input. The Bozak crossover has a box containing various values of capacitors with jumpers to accomondate different models of speakers. Yes, the wax capacitor has aged. I listened to them "as is" and I heard the potential of an outstanding pair speakers once restored. Pat Tobin, the Bozak guru, discovered there's a dip in the Bozak tweeter with the Bozak original crossover, and his mod will smooth it out, and leave the midrange and woofer unaltered. The Bozak 313 was to compete with the smaller AR, KLH and the like, but the 313 is still bigger, and heavier than it's competitors. With the smaller cabinet, I'll give up some bass responsive, but I think the result will be worthwhile. I'd like to have a pair of Bozak Concert Grand, but just don't have the room for them.

I will not use audiophile cap, maybe Solen or Dayton from Parts Express.

I will post the restoration process and result here.

rcag_ils · « **Reply #19 on:** 1 Apr 2009, 11:13 pm »

Wayner,

Thanks for the tip, I'll have to take them apart and see what shape the terminals are in. Your way is definitely more thorough. If I am lucky enough that the terminals are still intact, I may seal it with RTV for a quick and easy fix, but I'll have to see.

Thanks for the help.