Tube amp for PSB Synchrony One speakers?

[Karl Jeffs]

Hello All, I'm new to posting here but have perused the threads as an observer for quite some time. I'm trying to make a decision which is slowly driving me nuts. I bought a used pair of PSB Synchrony One's without realising my 35Wx2 PrimaLuna Prologue Classic wouldn't be able to drive them sufficiently. So I have decided to upgrade the amp to something that can power the speakers. I really would like to stay with tubes and have the opportunity to try the McIntosh MC275 and two MC75 monos at my local dealer. I can get a great deal on either set-up as the dealer is switching from selling McIntosh to PrimaLuna and therefore getting rid of their stock. I also have the option of the PrimaLuna Dialogue Premium HP integrated, also rated at 75Wx2 and considerably cheaper than the McIntoshs. My question is, will any of these choices do a respectable job with the speakers? If more info would help any advice, the only source is a Clearaudio Performance DC turntable with Maestro cart feeding into a CA Balance+ phonostage. The room is quite large approx 20x30ft. Really appreciate any advice!

 

[airtime]

If you can afford it go for the Mc75. Mono's are better with their separate power supplies, higher dynamic headroom and a tad lower damping factor. There are two Mc275s. Anniversary and IV. Both are about the same. It may be just me but I think that green LED effect is really cheesy looking, sorry.

The PL also uses the KT88 - go for the Gold Lions!!!!! However. The PL uses the KT120 to get the 100 watts - NOT a good sounding tube, just my opinion. The KT88 will give you the same power as the Macs. The EL34 - a HELL of a nice sounding tube will only get you around 22 watts at best.

All the smaller driver tubes on the PL are 12AU7. The only new production 12AU7 I've found to sound good are the TungSols. So good ones can be harder tubes to source if you want to tube roll. Which I love doing!

The Mac uses 12AT7 and 12AX7 - No shortage of tubes to try and roll there!

You have big speakers in a big room. Get the mono's that will give you that little extra push.

 

[Karl Jeffs]

Thanks airtime, great advice. I tried KT120s on my PL Prologue for a while and switched back to the EL34 which sounded much better. I really would like to stay with tubes if possible with the Synchrony Ones. I also posted this on the McIntosh page and the responses I've had so far is an SS amp will suit the speakers better and give me the power they deserve which is a shame because I'm really digging the look of MC75s!

 

[airtime]

Can you audition the 75's. I was never a big fan of the Mac SS amps. I say if you like tubes then DON'T switch to SS. You won't be happy.

 

[Karl Jeffs]

Yes I can audition the 75's and the 275 side-by-side with my own speakers. I'm just concerned I'll have power issues for the Synchrony One's, they're difficult to drive - 90dB, 4 Ohms sometimes dipping to 2 Ohms, rated 20-300W.

 

[airtime]

The 275 and 75 can handle a 2 ohm load. There is even a speaker tap for that. However I would try the 4 ohm taps first. And at a damping factor of 18 you will have more push than you think. Do audition the 75s. Unless you are driving them to ear bleeding levels you should have no problem. Ironically !!!! some of the older Mac gear DID have those problems with dips in impedance. They had a zener diode that would crap out when the impedance hit below 2 - boom.

 

[for_p1]

Yes I can audition the 75's and the 275 side-by-side with my own speakers. I'm just concerned I'll have power issues for the Synchrony One's, they're difficult to drive - 90dB, 4 Ohms sometimes dipping to 2 Ohms, rated 20-300W.

J8st do what I did - get both tube and solid state amplifier and use speaker switch to choose what amplifier you want to hear at the moment. But they should be rather different: mine are, for instance, 845 SET and 300W Bryston.

 

[cubdog]

Years ago when I bought a pair of Dahlquist DQ10s I auditioned them while being driven by a pair of MC 275 amps. I don't think I ever heard them sound better. I have a hard time believing they would not be up to driving your PSBs. Maybe, because I admit I haven't heard your speakers. I'll remain doubtful however.

 

[Son-of-Vere]

Bi-amp? Looks like a good candidate.

 

[PAGS]

How about a hybrid - tube pre, SS power? There's a nice Rogue Audio Sphinx for sale in Barter Town for $875. 100 wpc into 8 ohms, 200 wpc into 4 ohms. Of course, you'll have to pony up the cost of joining BT ($20 a year, I think.)