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My ipr1600 puts out 55vrms with 60 hz sine before hitting DDT, and it runs 4 t30 really nice..

osse wrote:My ipr1600 puts out 55vrms with 60 hz sine before hitting DDT, and it runs 4 t30 really nice..

If I was going to go down the Peavey route, I was thinking of the ipr1600 for my DR250s and the ipr3000 for my T39s.
(Although it would be nice to upgrade to ipr3000 and ipr5000 respectively ).

Nordo wrote:

osse wrote:My ipr1600 puts out 55vrms with 60 hz sine before hitting DDT, and it runs 4 t30 really nice..

If I was going to go down the Peavey route, I was thinking of the ipr1600 for my DR250s and the ipr3000 for my T39s.
(Although it would be nice to upgrade to ipr3000 and ipr5000 respectively ).

Sounds wise, as the t39 takes 60v and the 3000 should put out about 71!

Bigger amp would be more suited to 2ohm loads, correct?
3 or 4 T39s per channel... hmm... doable?

Maybe in Aussie but in USA you need to get into the power distribution business. The regular wall socket is 110v. Does IPR even do sub 4 ohm loads?

Gregory East wrote:Maybe in Aussie but in USA you need to get into the power distribution business. The regular wall socket is 110v. Does IPR even do sub 4 ohm loads?

According to peavey.com
the IPR1600 delivers 800W per channel @ 2ohms...

I wasn't aware of that. Interesting. I wonder how it'd cope with that.

A bit light for three, and at 4ohm possibly not quite enough grunt to push two. The 3000 would be more like it.

Hi All,

I have just relisted my JANDS 920 amps on ebay - but I have 3 left - so if you are interested -please call me on 07 5529 9969. Thanks

Can anyone point me to a topic (or external link) that explains output voltage testing of amplifiers and how to match that with BFM speakers.
I've had a good search through the BFM forum, but can find anything relevant.

Computer, MP3 player etc,
Line level to amp input at least (input both sides if your amp is capable of higher output one channel only driven), no cabs connected.
Pick a frequency, say 60 Hz sine wave.
Turn amp on, volume knobs to full.
Play frequency.
Measure voltage at outputs (easier if binding posts, if only speakon outputs you'll need to make up a test lead that separates + and -) with multimeter set on AC volts 200 scale.
If you don't think this is going to max out amp voltage, select different frequencies.
So that's testing...

Now to match that to BFM cabs:
In the plans it gives maximum voltages for your driver choice.
Same same sorta, no cabs connected to set it all up.
You want frequency into 1 channel of desk, as hot as it will ever be run, ideally just below clip.
You want your masters just below clip.
Output to amp. Somewhere in the chain you need a limiter on the output stage eg use a DCX2496. So your cabling may be Desk/DCX/Amp.
You know what your max voltage was from first test.
Running everything, reduce the limiter settings until your multimeter shows the desired voltage at amp output.
Note: you want to see the limiter light kicking in at this setting, but not constantly.
Amp output is now correct for your driver in BFM cab.

Addit: you have to be aware that anything that increases the signal upwards in terms of level from the settings you did your setup on, will require you start the whole process again.
eg, add a DEQ2496 before your DCX. Set the output switch on the back to +22dB, and increase the level of input and output from it too, and your output voltage at the amp will increase as well.

Hope this all makes sense...

chatterbox wrote:Hi All,

I have just relisted my JANDS 920 amps on ebay - but I have 3 left - so if you are interested -please call me on 07 5529 9969. Thanks

Hello and welcome!
It may have seemed the best place to put your ad, but there is a for sale section in the forum.
If you're pontins I bought my 920's off you last year...

Cheers, thanks Grant.

I've seen a few posts on setting limiters, but you've covered the lot nicely.
BTW, I picked up a DCX the other day on eBay. Hasn't arrived yet.
Still looking for a DEQ and some amps and a board.
All I wanted was to build some speakers, but it's blown out into a complete upgrade of the entire band's gear!!!!

About ply, we have a local plywood dealer (The Bunker, in Doonan). I can get C/D pine 1/2" 5 ply 2700x900(or may even be 1200) for $34.00 a sheet. They also have bending ply for the curved parts of the DR250s.
How far is Batlow to Noosa?

If your C/D is same as ours it's nfg for cabs. It will be full of knots on the C side and godknowswhat on the D.

Grant Bunter wrote:Pick a frequency, say 60 Hz sine wave. ... If you don't think this is going to max out amp voltage, select different frequencies.

Would it make sense to pick 3 (or 5) "forum standard" frequencies, say: 40, 60, 80, 100, and 125 or whatever? I guess then take an average or the highest, maybe?

Would that provide more consistent results or just be more work than it is worth?