djeickme75
11-07-2007, 12:42 PM
I recently picked up a pair of AS101 speakers. I am new to the vintage audio world and have some questions about upgrade/repair of these units.
The cabinets and drivers seem fine. Most of the questions revolve around the electronics.
1) Upgrading the caps in the crossover
Someone has already done a partial replacement of the caps but I don't know when and the quality of the replacement caps is marginal. I have not yet measure the origanl caps but I suspect based on what I have already read on the forum that they probably have drifted significantly. I have an original a manual on the way to confirm the original values for the caps but it seems from what I can tell that there is an 8uF cap and a 10uF and an 11uF in parallel to give 21uf cap. This would mean that I need an 8uF and a 21uF (or a combination of caps to give 21uF). I contacted Parts Connexxion and they suggested Mundorf Silver and Oil (the second from the top Mundorf cap, with the Silver and Gold being the top). Has anyone had any experience with these caps in vintage Lansings? How about any of the other contenders like Dueland, other members of the Mundorf line, modern production Jenson caps or Audio Note copper caps (the silver are interesting but the price is completely out to lunch)?
2) Internal wiring
I suspect that the original hookup wire is also a little past its prime. I am thinking of replacing with silver hook up wire (I already use homebrew silver interconnects in my system and am looking at switching to silver speaker cables as well). DH Labs has an appropriate hook up wire or I could use the braided silver wire that Home Grown Audio sells for interconnect purposes. Anyone with experience using silver wiring for the internal crossover to driver conections.
3) Damping the 811B horns
This has been done to death so I won't ask anything further about it
4) Moving the crossover external
I have thought about taking the crossover completely external and mounting in a wood box with the RFI blocking paper that Parts Connexxion sells. Has any one else taken their crossover external?
5) Adding a supper tweeter
I am not saying I am unhappy with the high frequency extension, I am just looking to play around a bit. I have thought of adding one of the Fostex horn supertweeters. They are over 100db efficient and seem like a reasonable match to the 811B to give it a bit more reach. They are also nice because they are designed to be free standing, so you can just plop them on top of the cabinet without any other mods being required. Has anyone tried these or other super tweeters to extend their 811B reach (I have forgotten the driver spec which I realize is certainly relavent to this discusison).
6) the L-Pad
I suspect the L Pad may also be a week link in the crossover. I am wondering about replacing it either with a new L-Pad (Fostex makes some that seem like they could work) or even using the Fostex transformer based attenuator instead of an LPad (which would probably move the crossover external given its size). Any experience with replacing the LPad? How about doing away with the Lpad all together an settling on a single level with a simple resistor? I am guessing you could just set the LPad to your desired level and the measure accross the LPads leads with a multimeter to get the value for the resistor.
Just to give some background. I am new to vintage audio. I am 32 and therefore missed the heyday for this gear. I have been into higher end audio for almost 15 years but have never really been keen on the "HiFi" kind of thing. Always more of a music lover first and gear second, hence the switch to vintage. I run a couple of different tube amps depending on my mood (300B SET or 6L6/5881 PP) with an Audible Illusions preamp (the original Mini Mite from the late 1970's, early 1980's) that has been heavily tweeked by Gilbert Yeung of Blue Circle Audio (a really neat manufacturer of tube and hybrid elctronics in Canada). While I do have a turntable (an old Oracle), I admit that I listen primarily to CDs. I have a very large listening room (almost 35 000 cubic feet, its an old converted church) but I only sit about 12-14 feet from the speakers (it depends on my wifes furniture placement of the day). I use a variety of homebrew cables with products from Furutech, Oyaide and Homegrown Audio playing strong roles. I listen to a lot of smaller scale vocal (think Johnny Cash, Frank Sinatra, a whole variety of modern singer/songwriters) but I do like to crank some rock, large scale orchestral stuff or even rap on occasion.
Any comments or advice on my repair and upgrade project would be appreciated.
Dan Eickmeier
The cabinets and drivers seem fine. Most of the questions revolve around the electronics.
1) Upgrading the caps in the crossover
Someone has already done a partial replacement of the caps but I don't know when and the quality of the replacement caps is marginal. I have not yet measure the origanl caps but I suspect based on what I have already read on the forum that they probably have drifted significantly. I have an original a manual on the way to confirm the original values for the caps but it seems from what I can tell that there is an 8uF cap and a 10uF and an 11uF in parallel to give 21uf cap. This would mean that I need an 8uF and a 21uF (or a combination of caps to give 21uF). I contacted Parts Connexxion and they suggested Mundorf Silver and Oil (the second from the top Mundorf cap, with the Silver and Gold being the top). Has anyone had any experience with these caps in vintage Lansings? How about any of the other contenders like Dueland, other members of the Mundorf line, modern production Jenson caps or Audio Note copper caps (the silver are interesting but the price is completely out to lunch)?
2) Internal wiring
I suspect that the original hookup wire is also a little past its prime. I am thinking of replacing with silver hook up wire (I already use homebrew silver interconnects in my system and am looking at switching to silver speaker cables as well). DH Labs has an appropriate hook up wire or I could use the braided silver wire that Home Grown Audio sells for interconnect purposes. Anyone with experience using silver wiring for the internal crossover to driver conections.
3) Damping the 811B horns
This has been done to death so I won't ask anything further about it
4) Moving the crossover external
I have thought about taking the crossover completely external and mounting in a wood box with the RFI blocking paper that Parts Connexxion sells. Has any one else taken their crossover external?
5) Adding a supper tweeter
I am not saying I am unhappy with the high frequency extension, I am just looking to play around a bit. I have thought of adding one of the Fostex horn supertweeters. They are over 100db efficient and seem like a reasonable match to the 811B to give it a bit more reach. They are also nice because they are designed to be free standing, so you can just plop them on top of the cabinet without any other mods being required. Has anyone tried these or other super tweeters to extend their 811B reach (I have forgotten the driver spec which I realize is certainly relavent to this discusison).
6) the L-Pad
I suspect the L Pad may also be a week link in the crossover. I am wondering about replacing it either with a new L-Pad (Fostex makes some that seem like they could work) or even using the Fostex transformer based attenuator instead of an LPad (which would probably move the crossover external given its size). Any experience with replacing the LPad? How about doing away with the Lpad all together an settling on a single level with a simple resistor? I am guessing you could just set the LPad to your desired level and the measure accross the LPads leads with a multimeter to get the value for the resistor.
Just to give some background. I am new to vintage audio. I am 32 and therefore missed the heyday for this gear. I have been into higher end audio for almost 15 years but have never really been keen on the "HiFi" kind of thing. Always more of a music lover first and gear second, hence the switch to vintage. I run a couple of different tube amps depending on my mood (300B SET or 6L6/5881 PP) with an Audible Illusions preamp (the original Mini Mite from the late 1970's, early 1980's) that has been heavily tweeked by Gilbert Yeung of Blue Circle Audio (a really neat manufacturer of tube and hybrid elctronics in Canada). While I do have a turntable (an old Oracle), I admit that I listen primarily to CDs. I have a very large listening room (almost 35 000 cubic feet, its an old converted church) but I only sit about 12-14 feet from the speakers (it depends on my wifes furniture placement of the day). I use a variety of homebrew cables with products from Furutech, Oyaide and Homegrown Audio playing strong roles. I listen to a lot of smaller scale vocal (think Johnny Cash, Frank Sinatra, a whole variety of modern singer/songwriters) but I do like to crank some rock, large scale orchestral stuff or even rap on occasion.
Any comments or advice on my repair and upgrade project would be appreciated.
Dan Eickmeier