michigannick
Well-Known Member
Glenn, have you ensured those meters are true? as the capacators of those things get old the peak movements of the needles will diminish .... 10 could really be a lot more ... just be careful ;-)
ADS-910's
- Thread starter GD70
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GD70
Lunatic Member
No meter check. I've had it for a week!
I'm assuming they are accurate based on my techs reported output of the other amp, which has not had any caps changed, but you could be right. Besides the volume level was about as loud as I would go, volume setting on the pre between the 10-11 o'clock position. Any louder and my ears would start to hurt!
I will have it checked now that you mentioned it, just to know. Thank you.
Glenn
michigannick
Well-Known Member
I phoned a friend who really knows the tech side of things (and loves audio) Anatec so hopefully he will weigh in . id just hate to see you go overboard but at 10 o'clock you probably are not ;-) (depending on gain or no gain pre amp)
GD70
Lunatic Member
Thanks for making that call, and I'll ask my tech about it with my other amp, see what he says about meter accuracy vs actual output.
The thing that amazed me about the 910's was at that volume, the woofers were barely moving, maybe a 1/4, 3/8ths movement at the most! It was clear these weren't even close to breaking a sweat! Just had me shaking my head, thinking holy sheit! Feeling the air move in the cave was crazy. Oh, my wife was not home at the time.
The thing that amazed me about the 910's was at that volume, the woofers were barely moving, maybe a 1/4, 3/8ths movement at the most! It was clear these weren't even close to breaking a sweat! Just had me shaking my head, thinking holy sheit! Feeling the air move in the cave was crazy. Oh, my wife was not home at the time.
soundmotor
super modified
Not in stock form. They do get much closer with a woofer swap. The original woofers in the L990 is a 206-0364. It is just barely up to the task with no margin. Push them hard and they run out of gas. Push them harder and the voice-coils bottom and bend. You can transform the speakers though if you find a set of 206-0369 woofers. It is a direct drop-in. Longer excursion, larger voice-coil & magnet, and much lower Q. It is just about perfectly aligned in the L990 cabinet and smooths out the bass response, goes deeper and takes a beating. The L880 responds identically with this woofer. The woofer was not used in production as those speakers were discontinued. The woofers however were used as service upgrades and swapped in place of the originals if there was a customer who kept blowing them up. You might be lucky and have those woofers installed already.
anatech
Audio service specialist
Hi Glenn,
Vu meters indicate average power levels with defined ballistics. So real Vu meters have defined characteristics. Your program peak levels will probably be 10 to 15 times what is indicated on a Vu meter. If the meters are simply average responding and not Vu meters, they do not have defined response characteristics and your ratios might be off. A good rule of thumb is to multiply your meter reading by at least 10. If you are using a dynamic CD, plan on 15 times what you are reading.
That should explain what you were seeing. Also, avoid setting off the clipping indicators, even if only briefly. It's too easy to wipe out the tweeters or flatten the voice coil former (as mentioned above).
-Chris
Vu meters indicate average power levels with defined ballistics. So real Vu meters have defined characteristics. Your program peak levels will probably be 10 to 15 times what is indicated on a Vu meter. If the meters are simply average responding and not Vu meters, they do not have defined response characteristics and your ratios might be off. A good rule of thumb is to multiply your meter reading by at least 10. If you are using a dynamic CD, plan on 15 times what you are reading.
That should explain what you were seeing. Also, avoid setting off the clipping indicators, even if only briefly. It's too easy to wipe out the tweeters or flatten the voice coil former (as mentioned above).
-Chris
michigannick
Well-Known Member
206-0369 woofers
Sound Motor, I looked on craigslist a few months ago and a girl was selling her late fathers spare gear which included a pair of ADS L-1590 woofers, i have 990s would these be a proper match do your knowledge? I do not have access to the 206- number as i sit .. my 990 woofers are fine as they sit but as you said they do run out of legs
Sound Motor, I looked on craigslist a few months ago and a girl was selling her late fathers spare gear which included a pair of ADS L-1590 woofers, i have 990s would these be a proper match do your knowledge? I do not have access to the 206- number as i sit .. my 990 woofers are fine as they sit but as you said they do run out of legs
michigannick
Well-Known Member
Glenn i was looking at the service manual on that JVC M-7050 impressive specs and good looks
GD70
Lunatic Member
Hey Chris,
Thanks for explaining this. What I was seeing made me think the 910's are extremely efficient! So then they were seeing more like 50-100 watts based on what you're saying.
A pic of the meters which show power output in watts.
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michigannick
Well-Known Member
Sorry were you saying something.. I was busy starting at your big bouncy ..... meters
GD70
Lunatic Member
Hey Nick,
Thanks for checking it out! It's a nice, clean, timeless design in my opinion and looks great with the cabinets.
I was pretty surprised when my tech said it was putting out 200 wpc!
Glenn
Blue Shadow
Waiting for Vintage Gear from this century
The difference here is the FTC mandated power rating of 150 watts per channel, at some distortion, into some load, both channels driven for a certain frequency response after a 'preconditioning' at a brutal power output until the unit cooks nicely compared to the hook it up and see what she'll do method which is common on the bench today. There should be a minimum of 10-20% more power from this method on all decent gear from back then. But whatever, 150 is stout and 200 is Fun toys!!
Anyone wanting to look over some power numbers check out classicaudio's for sale section and read their performance verification sheets at the bottom of the listings. Everything does a lot more than rated for the reason stated. But that 200 outta a 150 amp is stout, a couple other amps did that but not many.
soundmotor
super modified
L1590 woofers (206-0350 or 361) are 8-ohm. The 206-0369 (also called S10) is 4-ohm and matches the original L990 woofer. If the L1590 woofers were cheap, I would grab them on principle. There is always someone looking for spares and they aren't making more.
michigannick
Well-Known Member
oh for sure I grabbed them .. exactly as you said, on principal .. at one point i had over a dozen orphan ADS drivers but I needed a bunch of work done so i sent them to Richard in a bit of a trade .. i know he would get them back in use a lot quicker than I would.. (of course i kept extra drivers for the models i have where i could)
Blue Shadow
Waiting for Vintage Gear from this century
Let me add that the preconditioning is done at 1/3 rated power and this is one of the most demanding power output levels. More heat is produced and the amp is working hard. It is amazing that some of the tests of amps back then indicated that the amplifier reached thermal overload and shut down, cooled and switched back on to continue the test. I don't know the particulars of this, whether it needed to be a 1 hour test or if the signal needed to be reproduced for 1 hour. I believe the latter. I have been trying to learn more about the specifics as I bought my first big amp on the day the law was enacted, Nov 4, 1974.
But I'm looking at your statement, one of the guys that drops by for a listen on a regular basis understands the term I used, stout. If you spell it with a capital letter, Stout, he wants a thick, chewy beer, especially if it is enclosed in quotes.
michigannick
Well-Known Member
Stout 
GD70
Lunatic Member
Big fan of both types of STOUT!!