Make sure your amp is rated for 4 ohm loads.
bshorey
Super Member
A 1980 is probably worth 2-3 times what she was quoted to repair it. She could spend $500 buying another amp, or she could spend $1,000 to repair the 1980, and end up with something period correct, and with plenty of power to do the job.
I'd fix the 1980. What's she going to do with it if she goes for another amp?
bs
The RX-V1000 is an AVR, not a high current amp.
nj pheonix
Lunatic Member
I suspect several of the better techs here could fix that (right ) for less
Best advice, try it out first. If you find the need, go bigger. An M-85 or 2000 would be quite nice
Took a look, it's a 33lb receiver, true 100wpc amp section, able to handle 4 ohms with the 2 channels driven.
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onplane
What! No Wake???
If you'd like to solve this problem and spend the least amount of $'s, consider the Sherwood RX-5502. I bought one three months back for $160 delivered, brand new with two year manufacturer warantee.
What sets this unit apart from all the others is it's strictly a 2 channel receiver, but with 4 full range amps rated at 100 wpc @ 4 ohms. So with this unit, you would use the main amp to power the woofers and the room2 amp to power the lower mid, mid and tweeter. In short, you split the load between the two internal amps.
You further gain "voice control" over the AR9's, as you can vary the power sent to the respective halves.
Regards,
Jerry
What sets this unit apart from all the others is it's strictly a 2 channel receiver, but with 4 full range amps rated at 100 wpc @ 4 ohms. So with this unit, you would use the main amp to power the woofers and the room2 amp to power the lower mid, mid and tweeter. In short, you split the load between the two internal amps.
You further gain "voice control" over the AR9's, as you can vary the power sent to the respective halves.
Regards,
Jerry
Sherwood does not give a power output rating for the RX-5502 on a 4 ohm load. How is it performing with your 9's? They don't specifically say not to use 4 ohm speakers, unless paralleling more than two pairs which you would not have to when biamping the 9's. So it's a bit of a gray area with this unit.
onplane
What! No Wake???
According to Sherwood's data sheet, (see attached to my post) the amps are rated 70 wpc @ 8 ohms and 100 wpc @ 4 ohms.
I use it to drive pair of AR TSW 610's. These have the famous AR 12 in woofers with a 6.5 in mid and titanium domes.
Initially, I drove the speakers with the main amp alone and the 2nd amp turned off. I did this for several weeks and the unit performed flawlessly. The amp which died was rated at 175 wpc, but it always ran fairly warm. This unit runs cool in comparison. Almost no heat from the output device heat sinks, but I do feel a small amount of heat near the transformer and voltage regulators.
While the TSW 610's did NOT come from the factory with bi-amp terminals, I brought a separate wire out to drive the woofers independent from the other drivers (naturally, I left the low pass filter in place). So for the last 6 weeks I've been bi-amping and I love it. Altering speaker voicing is as simple as a few remote clicks.
Regards,
Jerry
Attachments
Paul1979
New Member
She has decided to get the SX-1980 fixed as it had given great service (with the pre amp) for 20 years. Her husband has just recently passed away and it is his system so she wants to keep faithful to that as it was his baby. He bought the 9's from Len Wallis Audio in Sydney in 1980 and has since had them fully restored 10 years ago. They are beautiful and shake the bloody house and windows!!
D'oh! Sorry I forgot you had posted that. I googled it up and found only the owners manual, in which the specs page does not list power output at 4 ohms. OK then. Carry on.
onplane
What! No Wake???
Tox, the manual is pretty hard to read and is confusing at best. They sort of imply that you can use 8 ohm speakers on A & B which puts the two sets in parallel with a resulting impedance of around 4 ohms. Again, I admit it's NOT as clear as it should be.
One thing I truly believe is that those high current draw woofers behave better when disconnected from the complex xover and other drivers. That is, behave better in the sense that the impedance over the range of interest is more stable.
Regards,
Jerry
That seems counterintuitive. The AR engineers spent a lot of time trying to make the speaker linear down to your pancreas without horrendous impedance dips. It's hard to imagine the speaker works better without a crossover. Playing devil's advocate here.
pognoot
Well-Known Member
That doesn't matter, it's quite capable in two channel operation. I would definitely try it out and see how it performs. What's the harm in that?
There's no harm as long as it's not your amp or speakers.
onplane
What! No Wake???
My fault for not describing clearly what I did and Yes, you are correct. I'd worry about driving the woofers without the low pass filter. So the xover in my TSW's still exists and is fully functional. What I did was separate the low pass filter from the balance of the xover. This minor change does have an impact on the impedance seen by the woofer amp. In short, the impedance seen by the woofer amp is more stable than the impedance seen by an amp driving a complete speaker system OVER THE WOOFER'S FREQUENCY RANGE.
I've actually measured this and was surprised by the difference.
Markoneswift
Quartz locked n ready to rock
I drove my AR90s with a Yorkville Beta 800 power amp, capable of 400 wpc into 4 ohm but able to go down to 2 ohm due to its massive transformer.
I seem to remember a thread on modifying the AR9 lower crossover. Was that you?
I'm trying to get my head around this and if there is another thread on it, I will happily stop hijacking this one.
onplane
What! No Wake???
I seem to remember a thread on modifying the AR9 lower crossover. Was that you?
I'm trying to get my head around this and if there is another thread on it, I will happily stop hijacking this one.
Nope, I would never touch that AR9 xover. It is one of the most complex xovers I've ever seen. Putting the two 12 inch woofers in parallel is quite a feat.
Now, on the AR LST's I've made multiple posts about eliminating the cap bank and transformer. To do this successfully, however, you pretty much have to bi-amp, which I think is a good thing on all of these power hungry AR's.
Regards,
Jerry