Using Equalizer as Preamp?

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Richard D

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I have a Souncraftsman SE450 equlaizer and a PL700 on the way. I want to run my series I Bose 901s with this(I have the correct Bose Active Equalizer for the speakers). Can I plug my satellite radio, MD player, etc into the eq and then to the amp, or do I need to use a separate preamp? I also want to run a subwoofer, I have both a powered on and non-powered. I realize this isn't the optimum setup. I intend to eventually get a preamp, but I am having a party next week and want to have music.
 
Richard D said:
I have a Souncraftsman SE450 equlaizer and a PL700 on the way. I want to run my series I Bose 901s with this(I have the correct Bose Active Equalizer for the speakers). Can I plug my satellite radio, MD player, etc into the eq and then to the amp, or do I need to use a separate preamp? I also want to run a subwoofer, I have both a powered on and non-powered. I realize this isn't the optimum setup. I intend to eventually get a preamp, but I am having a party next week and want to have music.
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I would say don't do it. I think I tried that with mine, but it was too noisy on the output. Might be a mismatch in impedance.
 
You could use a mixer in place of a pre amp if you had one handy. If you dont have a pre amp, your best bet would be, source through the 901 eq and into the power amp. Eliminate the other eq altogether. Hopefully the piece you choose to do it with has output volume. If youre using a powered sub you'd need to get a non powered signal to it. If the sub is not powered, youll need something other than whats running the 901's to power it. The 901 eq should not be feeding anything other than the 901's. In which case you'd need a pre amp with multiple power amp outputs. I suspect you may not need the sub with a 700 powering 901's, and in this situation, it will be more hassle then its worth, simply to have tunes. Worry about tunes first... if you can manage the sub in time for the bash then by all means giver. You definitely need a pre amp though.

Edit: You can forget vinyl without a preamp if that was a source you were hoping to use. A mixer likely wont have a phono either.
 
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Hey Fitz if you want to come all the way to Texas you are more than welcomed!

Thanks Bubba, I'll try that. I almost always listen to satellite radio, occasionally if I want to hear something specific I'll pull it up on youtube with my Iphone. Not exactly audiophile grade stuff, I know, but mostly for casual listening while working around the house or partying and shooting pool, etc. I really doubt the 901s are going to make the deep bass I like for some of the music I listen to, is there any particular feature in a pre-amp to look for to run a sub? I was thinking I'll try to find a PL 4000. Then I could divide the 700 watts from the amp to power both the 901s and the sub, no?
 
The 700 is not going to power those 90-1's and a sub. Separate subs are notorious power hogs, in fact a good sized sub should suck up every thing that 700 can put out. The 901's should be able too also. Do you have the owners manual for the EQ ? If you do look and see what the input and output impedence is. If you have an adapter for the 1/8 phono plug to a set of RCA plugs you can go directly from an Ipod to the 700.
 
No manual on the 901 eq, and the impedance isn't listed on the back. I have one of those adapter cords, I'm glad I can hook up directly to the amp. Would you recommend the PL4000 for a preamp for what I want to do? I'm on a pretty tight budget, so I'll have to wait a bit and shop around. I'll just run a powered sub if the 901s don't give me what I want.
 
If you're looking for smack you around bass the 901's aren't going to do that, but I know some that will...if you see a PL 4000 for sale run as far and as fast as you can the other way. That is the last pre you want to buy. It was a train wreck from the factory. The 2000-SerI's and II's are good. The 3300 is also excellent.
 
I suggest going through the 901 eq. If you need a pre amp to also run a sub, then you may have to look for a modern style receiver with multiple zone outputs... these can be used as pre amps... id suggest going another route though.
 
BubbaH said:
I suggest going through the 901 eq. If you need a pre amp to also run a sub, then you may have to look for a modern style receiver with multiple zone outputs... these can be used as pre amps... id suggest going another route though.
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Ben's right - the 901's sound like shit, I mean sound flat without their EQ in line so you'll need that for sure.

I believe you could use the Soundcraftsmen EQ as a sort of preamp but you wouldn't have a volume or balance control pot and I saw from some photos that SE-450 has two inputs available - LINE IN and TAPE IN. I don't know what the switcholgy is with this unit but it might work as a two source system.

One concern that's been expressed is that the source output voltage could be higher than the input sensitivity of the SC EQ so that might screw things up. In your favor is the fact that the 700 has one control pot per channel that could be a volume control in this situation.
 
Every pair of 901's I have ever owned I managed to blow up. Something about a certain frequency that they don't like. It is an inherent flaw (perhaps weakness would be a better word) in the eq's range of function? I am pretty sure a 700 will smoke 'em pretty easy if you use any type of tone control other then that Bose EQ when you put the gas to them. I also agree that they have no real bottomend, I was always disappointed with that aspect of them but they look cool hanging in fishing nets from the ceiling!!! Driven at normal to mid levels, they have fantastic imaging and presence, can't beat 'em

EDIT: Did a little reading, everything points to the eq as the source of whatever sound issues people have with 901's. Not sure why I lost three pairs with cooked drivers, back then I was using a Hafler amp. Some others have said upgrading the drivers was the key to making them better. I do know they are one hell of a party speaker though. Not as much bass as CV's and Infinity's. Get them up in the air and angle them downward though and they will part your hair

A guy I know who works at our local post office has a pair of the original Series I's. They look in pretty good shape still and he wants $300 for the pair. I would gamble on them again if I had the disposable income I used to for that price. The grill cloth needs to be redone on both due to an over zealous cat grooving to Cat Scratch Fever LMAO
 
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I think it's called "clipping". 901's don't like to be clipped either....
 
I run series V's with a VI eq. I have yet to clip them driving them with an 800 watt power amp. Series I's were supposed to be unlimited... I cant see a stock 700 getting the best of them... especially if the eq and drivers have been resto'd. I had VI's running off a VI eq, my brother has them now.

https://www.youtube.com/watch?v=7G-3-MQMZBo
 
Amen Bubba. The only time I heard anything bad with mine was when the Spec 2 clipped trying to drive them.
 
laatsch55 said:
Amen Bubba. The only time I heard anything bad with mine was when the Spec 2 clipped trying to drive them.
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Agreed Lee, the only time I personally have seen 901's act strange is from power amp issues. Believe me.... I know all about power amp issues....:banghead:
 
Northwinds said:
EDIT: Did a little reading, everything points to the eq as the source of whatever sound issues people have with 901's. Not sure why I lost three pairs with cooked drivers, back then I was using a Hafler amp. Some others have said upgrading the drivers was the key to making them better. I do know they are one hell of a party speaker though. Not as much bass as CV's and Infinity's. Get them up in the air and angle them downward though and they will part your hair

A guy I know who works at our local post office has a pair of the original Series I's. They look in pretty good shape still and he wants $300 for the pair. I would gamble on them again if I had the disposable income I used to for that price. The grill cloth needs to be redone on both due to an over zealous cat grooving to Cat Scratch Fever LMAO
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I think it would be safe to say that all 901 eq's of that age, should be re cap'd. A driver upgrade isnt necessary, but I have heard good things about that process.

300 bones is a steal for some series I's. Even if they do need some work. Check out the work I done on my V's.
 
BubbaH said:
I think it would be safe to say that all 901 eq's of that age, should be re cap'd. A driver upgrade isnt necessary, but I have heard good things about that process.

300 bones is a steal for some series I's. Even if they do need some work. Check out the work I done on my V's.
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Damn... GREAT job Ben! I always wanted to try refoaming myself. I wanted to do my Infinity 12" pair in the SM-120s I have but they are made a few different sizes so you have to be absolutely sure you get the right kit. The VC alignment using a CD or battery was new to me (you can tell I am more of a listener then a tinker). I figured a thin rolled up cardboard sheet would do the job since it will open to fit any size instantly :laughing9:

The drivers are all good on the pair of Ser 1's as I visually inspected them and he played a few tunes also. Still thinking about it but bucks are non-existent for buying any toys now. At 3pm, I am going over to negotiate a trade deal for a timecapsule in the original box Sansui 999 and a pair of Pioneer SC-907's. Got an extra electric guitar I rarely play to barter with
 
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Northwinds said:
Damn... GREAT job Ben! I always wanted to try refoaming myself. I wanted to do my Infinity 12" pair in the SM-120s I have but they are made a few different sizes so you have to be absolutely sure you get the right kit. The VC alignment using a CD or battery was new to me (you can tell I am more of a listener then a tinker). I figured a thin rolled up cardboard sheet would do the job since it will open to fit any size instantly :laughing9:

The drivers are all good on the pair of Ser 1's as I visually inspected them and he played a few tunes also. Still thinking about it but bucks are non-existent for buying any toys now. At 3pm, I am going over to negotiate a trade deal for a timecapsule in the original box Sansui 999 and a pair of Pioneer SC-907's. Got an extra electric guitar I rarely play to barter with
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An extra? I take it you are a guitar man as well then? I like to play myself, although making time for it these days seems to escape me. :laughing9: If youve ever noticed the long and picture filled thread over at AK Let's see all them axes, You can see a couple of my guitars. I have several acoustics now too though.
 
Beautiful job there Ben - thanks for sharing that. I really liked the looks of them after you renovated them. Did you ever do a recap or any other upgrades to the EQ? I've read an article or two that discusses this area. I've cleaned the switches and slides on mine and cleaned up the printed circuit board as it had a lot of rosin left from the factory fabrication. It sounds nice - I'm using a 700 Series I stock amp to drive the 901s and it sounds good.
 
I'll look Ben, I believe I have an extremely long photo post there also

Just got back from the dude's house and I have to say it was not a good experience. He saw the guitar and his eyes lit up but I said, I have to hear it first

Hooked everything up and him using his mp3 player as a source. Left channel did not work. Red flags arose quickly because he said he was running it last week. I suggested checking the fuse. Sure enough blown and the wrong type in there. This guy is a computer guy who thinks he is the ultimate electrician BTW. Starts putting random fuses in and I said, hey that's not safe. "It will be alright just to test" then POP blows another fuse when he turns it on, this time the power fuse went along with the same channel fuse. He has this bright idea to put higher rated fuses in and I am standing there speechless. Ok, amp came on and he cranked it halfway.... a mushroom cloud of smoke and that heavy acrid melted electronis stink filled his garage. We looked inside after the smoke cleared, heatsink on right was still freakin' hot, main power cap on the other channel had a "wave" in the top. Board that lines to the output caps had a few things toasted on it. Probably an easy repair for Joe, Lee and Jer but not for me. It had 4 fuses inside and none of them were toasted so the rest of the unit probably is fine. That right output board though...

I picked up my guitar case and said no deal
 
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