Tube preamp and powered woofers

[kirkawall]

Hi all,

I'm experimenting with a few preamp combos in my Vantage system, which uses a Quad CDP-2 or Cairn Fog as source, directly into either a Quad 909 or a McIntosh MC275. I'm demoing a very interesting little tube preamp called the Harmony, made by an Italian outfit, Synthesis. I'm struck by the improvement in dynamics, layering and spatial resolution with the active pre in the loop compared to the Quad/Cairn direct-in (Quad has an analog volume) but I'm wondering about the contribution of the tube pre to the bass response of the Vantages. It seems a little softer (pre still running in) so I'm wondering about the relative "immunity" of the powered woofers to the rolloff associated with some tube designs. Please forgive my ignorance here -- I'm a newbie to tube gear.

thanks and best,

k

 

[Tube60]

Hang tight until the thing's burned in. Is this preamp a zero feedback design? That could account for the somewhat softer bass. Also try to find out how much filtering it has in the B+. Does the Harmony have a tube rectifier? Bass won't be quite as tight in that case. Plenty of variables to work out!

 

[risabet]

Hang tight until the thing's burned in. Is this preamp a zero feedback design? That could account for the somewhat softer bass. Also try to find out how much filtering it has in the B+. Does the Harmony have a tube rectifier? Bass won't be quite as tight in that case. Plenty of variables to work out!

Agreed, let it burn in a while and then listen again. How do the impedances match up? Regarding the tube rectified products, I agree but I find tube rectifiers more harmonically rich and subjectively pleasing than SS rectified, though the latter may have tighter bass.

 

[kirkawall]

Hi,

Right -- I've just found out that one of the 4 12AU7s is blown, which has no doubt played a part in the looseness of the bass. There's little info on this design (I read no Italian) but I think it's tube-rectified and it has an output impedance of 1.5 kOhms, which ought to match the 909 (the Mac has adjustable volume on board so is easy to match). I do love the sound on most music and especially what it does for the Vantages, which suddenly seem to have come into their own. So, thanks for your advice all -- I'll let this burn in for a month or so and then do some critical listening. I must say, I'm finding that I prefer the sound of Harmony/909 to Harmony/MC275 or CDP/MC275. Weird how some components just seem to have that synergy...

thanks and best,

k

 

[Robin]

Interesting...

Hi,

Right -- I've just found out that one of the 4 12AU7s is blown, which has no doubt played a part in the looseness of the bass. There's little info on this design (I read no Italian) but I think it's tube-rectified and it has an output impedance of 1.5 kOhms, which ought to match the 909 (the Mac has adjustable volume on board so is easy to match). I do love the sound on most music and especially what it does for the Vantages, which suddenly seem to have come into their own. So, thanks for your advice all -- I'll let this burn in for a month or so and then do some critical listening. I must say, I'm finding that I prefer the sound of Harmony/909 to Harmony/MC275 or CDP/MC275. Weird how some components just seem to have that synergy...

thanks and best,

k

kirkawall,

Your demoing is interesting to me. As you will remember I am very interested in your MC275 amplifiers paired with your Vantages... :drool:

Sooo, you find the sound better with the Harmony and Quad 909 combo?

 

[kirkawall]

kirkawall,

Your demoing is interesting to me. As you will remember I am very interested in your MC275 amplifiers paired with your Vantages... :drool:

Sooo, you find the sound better with the Harmony and Quad 909 combo?

Hi Robin,

I guess it's too early too tell but, if not better, then more "complete." Naturally, if I had a C220 to hand... But this has made me realize just how much fun a tube pre can be and how with difficult loads it might make more sense than the SS pre/tube power. The MC275 is definitely a great amp and maybe great amps always need great preamps (I can't afford one yet). But, the 909 is also I think a much under-rated amp. So, better? Probably not. But more fun? Maybe. My taste in music is pretty eclectic and I've found the the Harmony/909 is a great all-rounder. I spend more time listening and less time tweaking with it in the system. I have no doubt that a few years from now when I can afford that high-end pre the MC275 will really shine. Or two of them will. And no, Robin, I won't be passing that MC 275 IV onto you just yet...

best,

k

 

[Tube60]

Hi,

Right -- I've just found out that one of the 4 12AU7s is blown, which has no doubt played a part in the looseness of the bass.
k

If you want to play with different 12au7s, let me know. I've got buckets of 'em.

 

[kirkawall]

If you want to play with different 12au7s, let me know. I've got buckets of 'em.

Hi,

Absolutely -- I've got a set of Rayethons on the way but I'd love to hear more and would certainly be interested in trying out some of these 12AU7 tubes. Please feel free to PM me with any details -- and thanks!!!

best,


k

 

[Tube60]

Hi,
Absolutely -- I've got a set of Rayethons on the way but I'd love to hear more and would certainly be interested in trying out some of these 12AU7 tubes. Please feel free to PM me with any details -- and thanks!!!
best,
k

Thanks for the PM, and I have many brands. IMO I think you'll like RCAs better, but that of course is an entirely subjective thing!