Biamping with Jolida/McCormack/Proceed


Hi All,

I've read many of the threads on biamping here. I apologize for asking what I’m sure is covered somewhere, but I ask because I couldn’t find enough specific information to reassure me. I did read enough to know what I want to do is less than ideal, but it’s all I can afford right now.

I have a chance to try out a Jolida 102b integrated amp (before buying it) biamped with my McCormack DNA-1 power amp. I would control them with my Proceed AVR preamp (using its DAC).

The Proceed has “remote” analog output RCA output*, plus a switch where I can let my Proceed’s volume control adjust both the main and the remote output simultaneously. The Jolida of course has its own volume control and analog inputs. (*The Proceed has main/remote xlr output too, but neither amp has balanced input.)

I’ve read various things including that if I set the volume control on the Jolida and leave it alone, it will work fine. But I have also read that the amps’ input impedance should match, and in another place that their input sensitivity should match. In neither case do they appear to precisely match:

Jolida 102b:
Input Impedance: = or < 250Kohms
Input Sensitivity: Max. 900mV for 20 watt output at 1KHz

McCormack DNA-1:
Input impedance: 100k ohms.
Input sensitivity: 1.2V.

I want to ask if I should try this, and if so how I should hook it up? My idea as of now is to use the Proceed’s remote output to drive the McCormack hooked to the low side of my speakers; and to use the main outputs to hook to the Jolida, and then to the mid/high side of my speakers.

If I need any sort of attenuation or gain adjustments besides what I can do with the Jolida, would you please suggest? And if the Jodida can be adjusted, how? Remember, I just want to try this out without investing much beyond the Jolida.

Thanks in advance for any suggestions you may have.
les3547
Wow, Steve, thank you so much for taking such extraordinary care in answering my questions. I certainly was not expecting such a coherent and detailed clarification. Many, many thanks.

I use an external crossover to bi-amp my own speakers. I chose to do so because I wanted to retain my relatively inefficient speakers -- I really like them -- while using low powered SET amps. I guess I got lucky. I am delighted with the result.

Regards,

Ivan
Glad to hear it's working well for you, Ivan. I get the impression that your amps are at least similar (if not identical) which really helps. And most electronic crossovers give you level adjustment, which allows you to use amps with mismatched input sensitivity. Then there is the question of which crossover to use, what crossover points, what slopes, etc., etc.... Easy to see why it's a confusing topic!

SM
I thought I'd update this thread now that a few years have gone by and I've had a bit more experience biamping. I still have Legacy speakers and still use a Proceed AVP as my preamp and DAC. However, I have changed amps several times. I write this for those of you who, like me, must use one system for both your music listening desires and for movies.

For someone on a limited budget, I still find the Proceed a fantastic tool for both music and movies. It has a great DAC that can decode for two channel music, it also does Dolby Digital (or DTS) for movies, and it has a lot of options for configuring one's system, including biamping.

So, after trying a little Jolida on the top end of biamping, I tried a more powerful tube amp so I wouldn't have to biamp, but it never did handle bass the way I wanted. I then went the other way, trying to find a SS amp that had a tube sound. I wasn't happy with that either. IMHO no SS amp can do what a tube amp does best, and no tube amp can do what a SS amp does best. Thus, I was right back to considering biamping again.

I'd sold my McCormack DNA-1 some time ago, but I still have a McCormack 3 channel HT-1 (225 RMS @ 4 ohms), and I recently acquired a Cayin a-50T tube amp. I also have a 100 watt Parasound. So my plan was to use the Cayin for the mids/highs, let two of the McCormack's channels drive the Legacy's woofers (and the remaining channel handle the center channel as normal), and then use the Parasound for surrounds.

Another part of the plan is to use the Proceed's controls so I can adjust gain as necessary between the two main amps. I use the subwoofer out and one of the "auxiliary" channels which can be configured as L&R stereo subs; that way bass can be adjusted as necessary in relation to the less-powerful Cayin handling the mids/highs. Very cool also is that the Proceed allows you to choose the crossover point from between 70 and 120 hertz. Since my speakers' woofers cross over at 100hz, I set the crossover point there and thus using the Proceed is like having an electronic crossover without having to reconstruct the speakers. All that's left to do is set the Proceed to crossover for my main speakers.

I am really pleased with this set up. An added bonus is using the system to watch regular TV. Since most TV is center channel, and I leave the McCormack on all the time (and the Parasound too), I can watch TV without turning on the Cayin; it sounds great using just the center, subs, and the surrounds. And then when I listen to music, I turn on the Cayin and simply choose "no surround" on the Proceed for normal two channel music.

One last thing I've tried that works well. I use MIT Shotgun S1 cables throughout my system, but I couldn't afford another pair of speaker cables and ICs just for woofers. In the past I've noticed silver cables, done right, produce very tight bass. So I used Signal Cable's Silver Resolution for the woofer cables and ICs. I have switched between the Signal SRs and my MITs to test them, and I think the Signal SR cables produce equal or even slightly tighter bass, and (compared to MIT) at a bargain price.