Using Bose 901's and equilizer from the 80's with a modern Amp

[Grimmy3290]

You CAN use the Bose 901 EQ with most all modern receivers (for just $20).
The Bose EQ has to be "between" the source (CD, Sirus/XM radio, computer, Amazon Alexa, etc.) and the power amp. So you plug in all of your music sources into an audio/video switcher. The switcher output then goes into the input jacks of the EQ. The EQ output goes into the AUX (or whichever) input of the receiver. I just keep my receiver always on AUX and choose which source I want to listen to on the switcher.
RCA or GE Pro 4-Device Audio/Video Switcher - $20 at Wal-Mart.

Even older post now lol. Will this switcher work with optical sound output from modern tv? I just bought new tv and want to get new receiver that can handle the optical audio from the tv and use the 901 speakers. Thanks if you can help me!

 

[Eppie]

Even older post now lol. Will this switcher work with optical sound output from modern tv? I just bought new tv and want to get new receiver that can handle the optical audio from the tv and use the 901 speakers. Thanks if you can help me!

https://www.amazon.com/optical-rca-converter/s?k=optical+to+rca+converter
Connect the optical out to an optical to RCA converter and connect that to the Bose EQ and then to the Aux in on an amplifier or receiver. If it's an older amp or receiver, you can use the tape monitor loop to connect the Bose EQ and use it on all sources and connect the TV adapter to the Aux. Any amp or receiver with both a pre-out and amp-in connection loop can also use the Bose EQ. Strictly for 2 channel audio, not surround, or you will end up EQ'ing your surrounds as well, so choose an appropriate receiver or integrated amp.

For surround systems, you need to connect the optical to RCA adapter to the receiver and the receiver must have pre-amp out for the main left+right. Connect the pre-amp out to the Bose EQ and then connect that to a separate amp. This requires a receiver and an amp. The amp runs the Bose and the receiver runs the surrounds.

 

[kunzeone]

You CAN use the Bose 901 EQ with most all modern receivers (for just $20).
The Bose EQ has to be "between" the source (CD, Sirus/XM radio, computer, Amazon Alexa, etc.) and the power amp. So you plug in all of your music sources into an audio/video switcher. The switcher output then goes into the input jacks of the EQ. The EQ output goes into the AUX (or whichever) input of the receiver. I just keep my receiver always on AUX and choose which source I want to listen to on the switcher.
RCA or GE Pro 4-Device Audio/Video Switcher - $20 at Wal-Mart.

This is very helpful! Which side of the Bose Equalizer should I use - the "Amplifier Connections" side or the "Tape Recorder Connections" side? Thanks!

 

[Eppie]

This is very helpful! Which side of the Bose Equalizer should I use - the "Amplifier Connections" side or the "Tape Recorder Connections" side? Thanks!

Amplifier connections. Here's a link to a manual in PDF format.

 

[kunzeone]

Thank you - my guess was the "Tape Recorder" side since I plan on using the 4 port switcher per TBGillespie's suggestion since I don't have a pre-amp out .. thus by using the 4 device switcher to select my component, the input would look like the selected component to the EQ.. sort of like the attached image
Thanks for the link, I have a copy of the 901 VI manual but not what you sent - very helpful!
I am awaiting the newly purchase 901 VI EQ and don't want to fry anything on day 1!

 

[kunzeone]

sorry.. not quite what I meant... I think it looks more like the attached image..
Ultimately I will purchase an audio receiver/amp with a preamp-out, but for now I am trying to power these from my existing receiver (which was purchased for a home entertainment system)

 

[Eppie]

@kunzeone The Bose EQ is a line level device, so it just needs a line level signal going in and then feeds the amplifier section, so the EQ'ing is done through the "amplifier connections" on the Bose. The ideal receiver is one with pre-amp out / main in so that all connected sources get EQ'd. Many older receivers have one or two tape recorder connections with a "tape monitor" feature that allows you to hear what the tape recorder is recording. Using the tape monitor gets around the problem of not having pre-out/main-in jacks as all other connected devices can be routed to the tape recorder, so the Bose can use the tape deck connections on the receiver but the tape monitor switch needs to be left on all of the time.

The issue became, what if you have only 1 tape recorder connection and no pre-out/main-in? The Bose EQ needs to use the tape recorder connections to route all sound through the EQ, so the EQ has a set of "tape recorder connections" in case you want to use both the EQ and a tape deck. EQ connects to tape 1 on the receiver and the tape deck connects to the EQ. If you don't have a tape deck, the tape connections on the EQ remain unused.

Modern receivers no longer have tape recorder connections so there is no "tape monitor" feature. Thus you either need a pre-out/main-in feature, a seperate amp and pre-amp, or you have to use a switch box to connect all of your devices to. The switch box connects to the Bose EQ input so that all sources get EQ'd, and then the EQ connects to any line level input on your receiver (typically the Aux connection).

 

[kunzeone]

Thank you - I genuinely appreciate the help! I'll post an update when I get it up and working.

 

[Spyderman]

My first post. I know this is an old post but it adresses my similar problem. I too have inherited a Series VI Bose 901 system with equilizer. I currently use a NAD C388 for 2 channel audio only and have only a phono hooked up to it. My NAD has a nice bluetooth system also. So I will be using only vinyl and bluetooth. Can I use my Bose 901s with my NAD C388. C388 is relatively modern so it has no Tape loop. I do have a Pre out but I do not appear to have a Main in.
I was thinking maybe I could run the Pre out to the Bose equilizer and hook my phono RCAs to the Tape input on the Bose equilizer, but won't I lose the ability to run my bluetooth music through the Bose equilizer? Any help is appreciated.

 

[lovinthehd]

Older integrated amps used to have processor/tape loops or a pre-out/main-in set of plugs, neither is on the C388 that I see. You have no way to take the equalized signal and amplify it (just get it out with pre-outs)....an external amp hooked up to the pre-outs could do it, tho (via the eq unit).

 

[TLS Guy]

My first post. I know this is an old post but it adresses my similar problem. I too have inherited a Series VI Bose 901 system with equilizer. I currently use a NAD C388 for 2 channel audio only and have only a phono hooked up to it. My NAD has a nice bluetooth system also. So I will be using only vinyl and bluetooth. Can I use my Bose 901s with my NAD C388. C388 is relatively modern so it has no Tape loop. I do have a Pre out but I do not appear to have a Main in.
I was thinking maybe I could run the Pre out to the Bose equilizer and hook my phono RCAs to the Tape input on the Bose equilizer, but won't I lose the ability to run my bluetooth music through the Bose equilizer? Any help is appreciated.

That won't work as there is no completed loop. The tape out sends the unequalized signal to the tape in on the equalizer. The output of the tape equalizer, tape out, then needs to go back to tape in, which you don't have. So you can't complete the loop. That system really does not work with modern systems, and to be honest those Bose 901s are perfectly dreadful speakers despite all the hype. I could never ever tolerate those speakers, even though that had a vogue in their day. I always listed to gear far, far better. Those drivers that Bose crammed into those cabinets could be bought for $3.75 each back in the day on the OEM market. That was Bose profiteering well beyond the unethical.

 

[Spyderman]

So if I add an external amp all of the power to the speakers would come from the external amp and the 150 wpc from my NAD C388 would be completely wasted?

 

[lovinthehd]

So if I add an external amp all of the power to the speakers would come from the external amp and the 150 wpc from my NAD C388 would be completely wasted?

Yep. You just have the wrong hardware for that speaker's gear needs. I'm with TLS on those speakers can be fun in a way if set up ideally but really aren't that great, particularly in the low end (which is what that eq is mostly trying to make up for).

 

[Spyderman]

Got it. Thank you so much. They were just something passed down and I wanted to give a try. I’ve got an old Yamaha receiver in the attic. I’ll hook them up with that and give them a listen. At 50 wpc not sure how much a listen it will be. My NAD C388 is currently powering some Apogees that I’m pretty happy with.

 

[lovinthehd]

Got it. Thank you so much. They were just something passed down and I wanted to give a try. I’ve got an old Yamaha receiver in the attic. I’ll hook them up with that and give them a listen. At 50 wpc not sure how much a listen it will be. My NAD C388 is currently powering some Apogees that I’m pretty happy with.

Give the other unit a try, if it has the loops needed the wattage is but about a 5 dB difference....unless that's critical.

 

[RodWhite]

You CAN use the Bose 901 EQ with most all modern receivers (for just $20).
The Bose EQ has to be "between" the source (CD, Sirus/XM radio, computer, Amazon Alexa, etc.) and the power amp. So you plug in all of your music sources into an audio/video switcher. The switcher output then goes into the input jacks of the EQ. The EQ output goes into the AUX (or whichever) input of the receiver. I just keep my receiver always on AUX and choose which source I want to listen to on the switcher.
RCA or GE Pro 4-Device Audio/Video Switcher - $20 at Wal-Mart.

Well it's 2024 and I've been running 901's for a long time and recently my NAD C370 amp has volume pot issues so I'm upgrading to the current NAD C399 which is the first amp I've owned which has no tape function.

This idea of putting the AV switch between the multiple sources and the EQ, then feeding the EQ to the amp is brilliant. This forum is in fact the only place I've found that has suggested such an idea.

I thank tbgillespie for the foresight of posting this idea 6 years after the original post so people like me can benefit from their knowledge.

Re the Bose 901's. My father purchased new 901 Series 1 more than fifty years ago and I followed his influence in 1986 and now have 4 Bose 901 Series 6 speakers. I have two on stands about hip height and two on stands at ceiling height, all in corners. My first amp was a second hand NAD 7400 monitor series and the second was a second hand NAD C370. I'm about to purchase a new NAD C399, hence the need for this solution.

All I would like to say about my system, NAD and Bose 901 is that everyone who hears the music is my house comments on how good it sounds and the louder it gets the better it sounds. What more do I want/need from a system.

 

[nanastasi]

Hello, would this solution work for a turntable as well? Do the any of the AV switch devices contain a phono in?

 

[RodWhite]

Hello, would this solution work for a turntable as well? Do the any of the AV switch devices contain a phono in?

I use an RIAA phono pre-amp to turn the phono signal into single ended L/R RCA then it becomes just one more input to the switch.

 

[TLS Guy]

I use an RIAA phono pre-amp to turn the phono signal into single ended L/R RCA then it becomes just one more input to the switch.

A switch is a passive device, and an RIAA input needs to be active. So to do what you want you would need a phono preamp ahead of one of those switcher inputs.

There are a couple of issues. First is that that NAD unit has limited digital functionality. It has eARC so you could use a TV as the HDMI switch. The other issue is that the Bose equalizer will not work with digital inputs.

Finally I have to say, I just fail to understand how anyone can enjoy those Bose 901 speakers. They are right up there with the worst I have ever heard. The measure badly and sound as bad as they measure. If they measure badly, especially that badly, they are just plain bad. So I just don't see the point of using them when there are so many better alternatives, which now includes just about any other speaker. And you can't add a sub to those speakers.

 

[nanastasi]

I use an RIAA phono pre-amp to turn the phono signal into single ended L/R RCA then it becomes just one more input to the switch.

Thank you. Is there a degradation in sound quality with all of these pass-throughs? Does the quality of the phono preamp have a significant impact? Any to recommend? Thanks again!