Does the VT100 MKII have a 4 ohm tap? Normally many Thiel speakers love solid state amps.
15 responses Add your response
The CS3.6's impedance magnitude and phase plot (fig.1) reveals a very low impedance value. The loudspeaker is under 3 ohms through most of the range, dropping to a minimum of 2.3 ohms at 3.6kHz (the cursor position). The low impedance value explains the CS3.6's need for the iron-fisted Mark Levinson No.23.5 to provide control in the bass; the CS3.6 would appear to be current-hungry.from Stereophile's measurement section (review linked below).
At 86dB with a minima of 2.5ohm on the impedance curve and staying below 3 ohm between 100Hz and looks like 10KHz, I would not pair it up with the ARC VT100. I would look for an easier load than the Thiel 3.6. Normally however, I would tell you to choose the speaker you like first and work your way backwards and get the appropriate amp to drive it. So if the Thiel 3.6s are doing it for you, than you may want to sell the ARC VT100 and get yourself a nice SS amp that has some oomph to it and that doubles its power as the impedance is halved. My 2c worth.
Unsound and Cmalak, I do not see in the manual where they say a VAC 30/30 class A amp will not work. I guess the VAC design studio was wrong. The Thiel manual says that that you should use a 100 watt amp. Is that 100 class A or class a/b? Are they they the same, I think not, my 30 watt class A amp as you infer will not work but my VAC 100 watt class a/b will? Both VAC amps can drive the same speakers, although I believe the 30 watt class A amp has more drive than the well reviewed 100 watt a/b amp.
On a side note I remember reading an article(Audio, Absolute Sound or Stereophile)years ago, that a high percentage of Thiel customers used Adcom 545 and 555 amps. Ouch that must of hurt ones ears, metal and solid state.
My Thiels sounded like crap until I finlly bought a Threshold SA3. Only 50 watts but high current and smooth. Lovely combo. One of the stupidest things I've done in audio was to sell this amp when I sold my speakers because my new speakers needed more power, lots more. I've never used tube amps with Thiels but I did use a tube pre-amp in combo with the Threshold. Sounded pretty good!
Jab, I tried Adcom and Perreauxs - my ears still hurt! :-)
If the amp is comfortable at 2 ohms and the room is not too large, it should work fine. The Thiels crave current drive, not necessarily high wattage. If they don't get the current they need, they will sound bright and thin. Also, you should have 3 feet or more open to the sides and shouldn't sit closer than 8 feet from them.
If you give them those things, they are a delight, and one of the biggest bargains in used gear.
I have owned a pair of 3.6 since I bought them new in 1995.
IMO, they need a beefy SS amp to get them going. When I originally drove them with a Hafler 550 (255wpc) amp, I could not make them sing. Don't get me wrong, the sound was nice, but if you want them to sound their best, a powerful amp is a must.
Unsound, I used (and still do) an ARC SP10II. It was revelatory in its hey day. I wasn't so wild about the matching D115II though. Phono stage is still pretty good. And if I ever find some mint SA 1's I'll buy them just for the nostalgia effect if nothing else. :-)
BTW, I'm assuming you are familiar with Thresholds 'optical bias' which was introduced after the initial production of the SA series. Did you find it added to the sound, quality wise? I never heard it but the feedback I got was that it sort of brighten them up a bit.