Pioneer SX 1980 as preamp?

elmostro

Active Member
i have a emotiva XPA gen 3 and that i'm want to use the with pioneer sx1980 preamp to drive a pair of 4ohms speakers, since the 1980 can only drive 8ohm loads i got the new emotiva amp mentioned above to take care of that. but while searching online i found this. i need advice thanks.

this is what i found.
(this is absolutely wrong most vintage amplifiers have inputs with a sensitivity of 150-200 mv try to connect a modern source on them like a CD player or a DAC and you will partially kill a very useful area of dynamics

Add to the above that some of them have gain ...or plenty of gain on the preamp ( expected you need to ""boost ""200 mv to something like 1 volt )

The result with a modern source is that everything on the preamp is going to be too much ...Volume knob is going to kick in someway too fast loudness function is going to be almost useless since added tone will be too much ...

Another complication will be that some of these amplifiers base the tone controls sitting on the feedback node of the main amplifier while the actual tone control has no active parts ...that will be also risky to ""brake"" from pre and main amp.


Finally and eventhough some of these circuits are very musical and provide very sweet but unreal sonics most of the designs especially with today's standards have horrible crosstalk and Chanel separation issues ...That it shelf is serious draw back even more serious than the gain issues

So its a NO big time !!!

what you guys think. what should i do?
 
What you have written is confusing and very poor english. I will try to make some sense out of your situation.
You have to figure out your system gain configuration.
If you have a sx-1980 and a XPA gen 3 class H amplifier, then the sx-1980 is a waste of time/money.
From what I have read, a XPA gen 3 class H is a monoblock, so you need 2 of them for stereo.
https://emotiva.com/products/amplifiers/xpa-1
If you bought such a power house amp, I would think the persons you bought it from, would advise you on a proper system setup.
If you are using a CD as your only music source, you do not even need a pre-amp with lots of gain, all you need is a passive volume, possible passive tone control and a active line buffer(maybe a bit of gain to compensate for a passive tome control, if it is used) to drive the amp, since the CD puts out enough signal to drive most power amps to full output.
The XPA-1 is 600W into 8 ohms which is 69.3V rms, gain is 29 dB or 28.18, so input sensitivity is 69.3/28.18=2.45Vrms
For the sx-1980, it has a 2V power amp sensitivity, it has a pre-amp gain of 2/150mV= 13.3 or 22.5dB
So based on these numbers your pre-amp needs very little gain.
 
I find it hard to believe that an SX 1980 can't drive 4 ohm load. I have an SX D7000 which is a fair bit smaller and it has no problem with 4 ohm loads.
 
The 1980's Drive Voltage Limiter, acts up when the output is near 300 watts continuous @ 4 ohms. Better be wearing a headset :D

power limiter.PNG
 
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all i need to know if by me using the pioneer as a preamp with the emotiva amp to drive 4ohms speaker is going to cause any damage to any of my equipment. thanks
Watch out for turn on/off thumps/glitches when you power on/off the sx-1980 by itself as a pre-amp only, with speakers connected to the amp, since the sx-1980 does not have any way to suppress these glitches. It would require modification to suppress these pre-amp section glitches. A sort of fault in the design using the sx-1980 as a pre-amp only. Other dedicated pre-amp's have this feature.
So if the speakers are connected to the power amp with no isolation then
1) power on sequence, would be to power on sx-1980 first then wait a few seconds, then power on the emotiva amp.
2) power off sequence, would be to power off the emotiva amp first, then power off sx-1980 last.
If you have the speakers isolated by switches then you could power them both up or off in any order as long as the speakers are disconnected form the power amp o/p until things settle.

Be weary of these power limiter designs as they tend to fry tweeters in quick order.
 
i have a emotiva XPA gen 3 and that i'm want to use the with pioneer sx1980 preamp to drive a pair of 4ohms speakers, since the 1980 can only drive 8ohm loads i got the new emotiva amp mentioned above to take care of that. but while searching online i found this. i need advice thanks.

this is what i found.
(this is absolutely wrong most vintage amplifiers have inputs with a sensitivity of 150-200 mv try to connect a modern source on them like a CD player or a DAC and you will partially kill a very useful area of dynamics

Add to the above that some of them have gain ...or plenty of gain on the preamp ( expected you need to ""boost ""200 mv to something like 1 volt )

The result with a modern source is that everything on the preamp is going to be too much ...Volume knob is going to kick in someway too fast loudness function is going to be almost useless since added tone will be too much ...

Another complication will be that some of these amplifiers base the tone controls sitting on the feedback node of the main amplifier while the actual tone control has no active parts ...that will be also risky to ""brake"" from pre and main amp.


Finally and eventhough some of these circuits are very musical and provide very sweet but unreal sonics most of the designs especially with today's standards have horrible crosstalk and Chanel separation issues ...That it shelf is serious draw back even more serious than the gain issues

So its a NO big time !!!

what you guys think. what should i do?
If this is your question, your 1980 pioneer preamp output simply has 2v,......... the xpa needs 1.5v to produce maximum output,......sooo the 1980 has a little more voltage (+. 5v) than is required, funny its almost always the other way around,...... in most other cases people have a .775 voltage pre out receiver,........ into a 2v amp input. the latter is where most complaints are from, because of preouts with too low of a voltage output,.....does not get total performance from some amps. Try it, your volume knob may be touchy. its not a horrible match. you could try the -db attenuator button if the 1980 has one.
 
thanks for all your responses. rcs16 i will do a your power sequence till i decide which preamp to get a new for my new setup.
thanks
 
The SX-1980 has a nice pre-amp in it. If you are adverse /skilled, you could do a rather easy mod to include a pre-amp section o/p relay to delay turn on and have a quick turn off. Basically duplicate part of the speaker protection circuit using another PAxxxx chip or there are many other easy ckt design options to use.
 
thanks for the help. i just decided to buy the emotiva xsp1 to match the amp and use the sx1980 with my other setup and be hassle and trouble free. thanks for all you guys help.
 
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