Wiring from 150b to integrated amp?

#1

Hey, just picked up a 150B and setting it up. I’m going to use it with my McIntosh MA7900.

I’d like some advice on the best way to wire it based on everyone’s suggestions.

I have SVS XLR and regular L/R kimber cable PB&J cables and could use either.

I am a little confused about what inputs I’d use for either of those setups, and what voltage setting you’d recommend for each.

For example, am I going to want to connect the kimber cable PB& J L/R cables to an input like the “aux” input on the McIntosh, or would I be pulling the bridges and using the “pwr amp” setting? And then what voltage setting when changing the pre out settings?

If I use the xlr cables, what settings would I want for the 150b?

Presuming I’d be using the dac/preamp in the 150b and going analog out to the McIntosh with those cables, don’t want to turn it on and run it before I am sure I fully understand.

Appreciate any help and happy holidays!

#2

I use my 150b with a McIntosh C53 preamp.

You can use the 150b as a DAC which will utilize the analog outputs of the 150b. I would recommend using the XLR balanced outputs of the 150b with the XLR balanced inputs of the 7900. Alternatively, you can use the RCA connections - but the balanced should provide the lowest noise level. I set the pre-out level on the 150b to 5000mv. I disable the software volume control on the 150b so that it fixes the output; this way the volume is controlled by the preamp and the volume control of the 150b is disabled.

You could also bypass the DAC portion of the 150b and feed the 7900 digitally using USB or one of the other digital inputs. In this scenario, the 7900 is the DAC (digital to analog converter). You will need those type of cables to do this.

Both DACs are very good. Some people like the DAC in the 150b, others like an external DAC (either like your 7900 or a separate DAC).

I have my system setup for both analog and digital feeds to my preamp.

I suggest that you try the DAC of the 150b and see how you like the sound.

#3

Ok thanks, this is all very helpful and exactly the kind of answer I was hoping for.

Just thought of something else I forgot to ask in my previous post. Do you think I should expect approximately the same level of volume/amplification if I use the xlr as compared to an optical or digital coaxial connection?

I guess what I’m wondering is if you think I’ll have to turn the volume up on the McIntosh a lot more with the analog setup, which would be using the DAC and preamp in the 150B instead; or if switching between the digital and analog inputs would result in similar volume levels/amounts of pre amplification overall?

The way my thinking goes here is that part of the choice on how to connect might relate to the overall level of sound/pre amplification? Or is this not a good way to look at the options,

Maybe instead, there is a way to equalize the volumes between the two ways of connecting?

Any comments you might have for me on thag would be appreciated.

Really looking forward to getting it set up and listening to the side by side differences with the digital vs analog connection methods.

#4

The pre-out level on the 150b is a way to “equalize” the volume level so the 150b matches the sound level of other outputs. This is on the analog side. So, you could play with different output levels - I use 5000mV on my setup. The 7900 should support all pre-out levels without overdriving the preamp stage. 5000 or the max 6500 would be fine, but would be louder on the 6500 setting. It’s all relative to the volume knob of the 7900 - I typically play my system with the McIntosh volume at around 20%. 30 to 40% is loud.

If you bypass the analog outputs of the 150b and use a digital output from the 150b, then the 7900 will handle the analog conversion and more likely match the volume levels. But if you are using other analog input sources (eg turntable, tape decks, CD etc.), you want to do level matching across them - next paragraph.

McIntosh also has the capability to adjust the relative db settings across your various sources used on your 7900 receiver. You could use that as well to tweak the volume and matching across devices. This is available to match across all your devices.

Note, that if you use the 150b with a preamp, I suggest that you turn off the software volume control on the 150b. That way the only volume control used is on the McIntosh 7900. The software volume control of the 150b is there for when using the 150b as a preamp with a power amp. So may use it to control volume with the Rose app, but you have two volume levels to adjust - I suggest to avoid that in this when using a separate preamp.

#5

Thanks again, I’ll get everything set up this weekend and then chime in again if I have any other questions.

Appreciate the help and information.