1594A in use

[Audio_by_Goodwill]

I've got a pair of 94As and a single 90A that I've tried selling or trading several times. Each time, I get little or no interest, so after letting them season in the basement awhile longer I finally decided to bring one of the 94As upstairs. I hooked it up to one to an old Hitachi cd player and my 9864-8A (Engine), and have been enjoying it for the last few days. However, I do have some questions.

I know the 1594A is a positive ground amp. What should that mean to me, practically speaking?

I'm not using a Pre-amp of any kind. I cut a cheap pair of RCAs in two and have both the left and right sides connected to the input of the amp...... am I hurting anything doing such? I know there are black boxes that will combine signals but I don't know what they are called.....no, I don't mean a mixer.

The volume doesn't seem to be as loud as I think it should given the amp is a 100 watt amp. The input impedance on the amp is supposed to be 15000 ohms, and I have no idea what the cd player output is. I don't know enough about impedance, in this situation to know what's right and whats wrong. Would an impedance mis-match explain my volume level being a bit low? It's listenable, and will get loud if I turn it up, but given I'm using horns I think the amp is running out of steam early.

[oface1]

Hey AbGW,

So these speakers you talk about, they are a duplex like a 604 on steroids then? The docs say a 515 mated to an 299 driver......Man that is one big hf driver or is it two separate components , woofer mated to the cab with the hf driver mated to a hf horn?? I am lost here.. could not find any other docs or cutaway pics to give me a good mental pic....


Sorry can't help ya on the maps ......


-chris

[Audio_by_Goodwill]

It's built like a 604, but with a large format driver, and the HF horn is removable, and extends to the end of the LF horn. The horn is actually mounted to the cabinet...... it's just too big to be attached to the driver, like a 604.

The Altec Pro site has info on it, and the rest of the series. I beleive it was Bill's baby.

http://www.altecpro.com/pdfs/vintage...t%20Matrix.pdf

DTS645A...... same hardware with exception of the cabinet.

http://www.altecpro.com/pdfs/vintage...r%20System.pdf

Here's the info from Lansing Heritage:

9864 It's got a great cut-away on the "cover".

[oface1]

Wow....did not know that...

Thanks for the info... guess I did not look hard enough for it...


-chris

[whitebroncoii]

A positive grounded amplifier should be transparent to the user.

It is my understanding that running the left and right signal output together without proper summing can cause damage to some stereo sources. If the stereo source has low output impedance, the outputs are driving almost a short circuit. A series resistor of 39k or 44k ohms will sum the left/right properly without loading the source. This would be a pair or resistors that are tied together at pin 1 on your 1594A with the left signal (+) on one resistor and the right signal (+) on the other. The shields of the left/right source signal are tied together on pin 2.

The line output of most consumer products is "-10dB" where the 1594A needs 0dB at full volume to reach maximum power. A 20dB pre-amp will raise the CD output level to well over the needed 0dB and the 1594A volume control gives you a wide range of adjustment.