what happens if you connect a 70v speaker to an 8 ohm amp

1. Came across an old Altec 1590c rack mountain amp, information technology's an early on SS amp from what I can tell. The spec sail at Lansing Heritage says it has outputs for 70V through 200V distribution systems, also lists various output impedances from 25 ohms on upwardly. If you wanted to utilize this to power a subwoofer, for example, could information technology be washed? Does it need an extra impedance matching transformer?

   Please annals to disable this ad.

2. Yep! And I have a few that proceed with my Bogen M-120 PA amplifier.

   Got whatever pics?

3. Call back I got the answer to my question - a matching transformer.

   PE has one merely it appears to exist designed to piece of work the other way - i.due east. connecting an eight ohm amp to a 70V speaker/distribution system. Question, would information technology work the other direction? Tin can information technology handle the same 100W if it's input into the 70V side to use with 8 ohm speaks?

5. Here's a film of the beastie. It's in the bottom of the cabinet.

   Attached Files:

   • 
   Please annals to disable this ad.

6. Trouble is, even if that PE transformer works, information technology would toll me mode more than what I have in the amp. It seems this amp is destined for PA utilize unless someone happens to have a big matching transformer laying around and doesn't take to purchase 1.

7. I'm not certain if the transformer in the link will piece of work in reverse for your Altec amplifier, only I do know they make them specifically for 70 volt input with different wattage output.

   I'll have to dig 1 of mine out of the barn and accept some pics to show you which ones I accept for my PA amplifier.

8. I have a feeling it will not. They as well sell modest xmfrs intended to go with each speaker in a distribution organization, rated 10W or 15W each. These adapt the 8 ohm speakers to the amp output which is what I'g looking to exercise. Only to run a big sub you'd need a transformer rated at a lot more watts than these. Once again, probably looking at big bucks for one that size if it could exist found.

9. I constitute a smaller 70 volt transformer pictured here, but I accept a bigger one with 15, xx, and 25 watt taps that is buried somewhere.

   I really don't call up that they are that expensive simply you lot could look at the Bogen website or the Hammond transformer website and run across what's available.

   If yous pull that Altec amplifier out of the chiffonier and have a look run into, it may have taps for 8Ω speakers.

   Attached Files:

   Please register to disable this ad.

11. Thanks for the link. I noticed they rate these 100Hz - 9 KHz - not exactly hi fi nor suitable for much bass on the depression end if you were going to use this matter to power a bass chiffonier.

    I looked at the 1590E spec sheet on the Heritage website and information technology lists all the impedance taps only none of them are below 25 ohms. This is the C model but I accept not been able to observe a manual for anything but the Eastward today.

    I may go have a look to verify the outputs, might exist the only way to exist sure.

12. I have some Altec/Peerless 15067'southward.

13. Thanks Bowtie I will look those upwards.

    I looked at this amp last dark. It had input terminals and DC terminals for a bombardment supply, simply no bodily output terminals that I could see. Had a couple of huge Peerless ability trannies on it, really built.

    It did take an octal socket marked 15095 Transformer. I was thinking this might exist where an output transformer is supposed to plug in but there was no sign of one. There was a piddling fragmentary shot glass sized transformer marked 150 and 600 ohms, perhaps this was a step up transformer for a turntable? Actually that'south what the 15095 is co-ordinate to Google, but the one mounted in the cabinet wasn't hooked up to this socket.

    Anyway I couldn't discover any outputs on the darn matter. I didn't bring it home but the guy says if no i buys it soon information technology may be offered for free in which case I'd probably snag it just to preserve it or for parts. Looks like it would make a neat footing for a guitar amp if the wiring could be sorted out, just not particularly good for hi fi which is what I was looking for.

    Please register to disable this ad.

14. I use these at piece of work, but not for How-do-you-do-Fi.

    Rob

15. Where?

    That's not correct.

    All versions of 15XX series solid state amplifiers are rated 20-20,000 +/- 1db.

    The 1590C should accept a iv.5 ohm tap.

    Remove the 4 large philips head screws on the front panel, it will open/hinge down.

16. 

    sregor AK Subscriber Subscriber

    Small transformer 600 and 150 ohms is probably an input transformer (balanced). If you want to experiment, I accept a 60W transformer I pulled from some speakers with 25 , 70 100 volt inputs and iv and 8 ohm outputs. http://www.audiokarma.org/forums/attachment.php?attachmentid=405857&d=1359347564

    Transformers in general take trouble with very low frequencies - I personally would go plate amp with xover route, as there are a lot of good for the money units out there. YMMV

17. I was referring to the Hammond transformers that centurytek posted a link to, not the amp itself.

    Thank you for that info on removing the front panel! If it has a 4.5 ohm tap I'm in business and will snag this thing for sure. :thmbsp:

    robisme and sregor, thanks for your posts.

    Delight annals to disable this advertisement.

18. Doooooooooh! That makes sense at present.

    15067 is flat from 35hz to at least 15khz @150wrms, PM me if you demand me to dig for em.

19. Someplace in my brain is that a seventy Volt output amplifier can exist tested with a xvi Ohm load, simply don't concur me to it.

    Mark T.

20. Here is a table the shows the reflected impedance unlike power level taps on the speaker terminate transformer in a 70.seven volt arrangement.

    That is the load that the output of the 70.7 volt tap on the amplifier will see when the speaker end transformer is tapped at the various wattages.

    Equally y'all can run across the impedance when using a i watt tap on transformer would be 5000 Ohms.

    You tin figure out the reflected impedance for any power level tap that might be on the speaker end transformer.

    One can also calculate the impedances that would be seen on other constant voltage taps on the amplifier. Of course the voltage is not abiding.

    Just some insight into the earth of constant voltage audio distribution systems.

    Just as in the output transformers used in our audio applications, size and the architecture of the transformer are important.

    Fastened Files:

    • 

Share This Page

crosleysirsenes.blogspot.com

Source: https://audiokarma.org/forums/index.php?threads%2Fhow-to-use-a-70v-output-amp-for-8-ohm-speakers.533077%2F

Share this post