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Picked up a set of Thiel CS3.5 - Amplifier Recommendations?

D

Decibel_116

AK Subscriber
So I picked up a nice set of vintage Thiel CS3.5 speakers last week. I have done some research and apparently these are very inefficient speakers and require a high current amp designed to drive 4 ohm loads well. I am looking for some recommendations for an amplifier that will be a good match for these. Vintage or new doesn't really matter that much. I would even consider a professional series amp if the distortion and S/N ratings are in the correct range. I have a couple of receivers in the 100 - 120 watt/ch range with < .005% THD @ 8 ohms. Neither have published specs for 4 ohm loads. I also have a Kenwood Basic C2 preamp that I could use with a separate power amplifier. I have used both Crown and QSC amps in live sound applications before with great success but don't know how well they would fare in a home listening environment. I was also looking at a local CL listing for a Denon power amp for $250 with 150 watts/ch @ 8 ohms. There is not much else here locally used. I looked at the Emotiva amps on Amazon and they seem nice. Opinions, suggestions? Thanks.
 
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I recently ran a friends pair of 3.5's with a Soundcraftsmen amp and they seemed to play well together. I can't remember the model number off hand but I believe that amp pushes around 400 watts into 4 ohms. We where using a GAS Theobe as a pre.
 
They're not very inefficient (well, technically they are, but so are all speakers). The sensitivity is normal if not slightly above average, rated 88dB/W/m.

And, despite having a 4-ohm nominal rating the impedance curve is rather benign so they're not a difficult "amp killer"-type load.

Do you have the EQ too?

FWIW, I have CS3.6 and despite having lower impedance they seem to work OK with a wide range of amps. That said, all the amps I typically use with them have min impedance rated 2 ohms or lower.
 
sheltie dave said:
emotiva(new) or Acuphase(old) both play well with Thiels. Crowns have too much grain at the top end to be nice.
Click to expand...

That confirms what I was thinking with the pro amps. I didn't think about the Accuphase.

fishondwan said:
I recently ran a friends pair of 3.5's with a Soundcraftsmen amp and they seemed to play well together. I can't remember the model number off hand but I believe that amp pushes around 400 watts into 4 ohms. We where using a GAS Theobe as a pre.
Click to expand...

The GAS Theobe is a new one to me. Thanks for the info.

whoaru99 said:
They're not very inefficient (well, technically they are, but so are all speakers). The sensitivity is normal if not slightly above average, rated 88dB/W/m.

And, despite having a 4-ohm nominal rating the impedance curve is rather benign so they're not a difficult "amp killer"-type load.

Do you have the EQ too?

FWIW, I have CS3.6 and despite having lower impedance they seem to work OK with a wide range of amps. That said, all the amps I typically use with them have min impedance rated 2 ohms or lower.
Click to expand...

I have read conflicting information about the efficiency on the web. The manual says a minimum of 50 watts which is not much power. I can't imagine that possibly being enough power for these speakers, especially with the bass equalizer which mine did not come with. I happened to find the equalizer on eBay and won the auction yesterday. I'm not sure it is really necessary, but I want to have the complete system whether or not I end up using it. The Thiels are going to end up in my main 2 channel system for listening to vinyl, but I may try them later today with my Sony ES HTR in 2 channel mode and have the room equalization feature compensate for the bass response while I am waiting for the Thiel EQ. It has a 4 ohm spec of 120 watts RMS/ch minimum @ 4 ohms with 0.15% (both channels driven). I figure I may get an idea what these are capable of by listening to an SACD or two. Firstly, I will need to get someone to help me move these things. These beasts are heavy!

Thanks for the replies!
David
 
I got a great deal on some Thiel 2.2's a few years ago. I paired it with a Cambridge 840a amp w/ 125wpc that I got used on Audiogon. It works great and I have no complaints but still wish I had shelled out the extra $ for a vintage receiver.
 
FWIW, I've used my Thiel CS3.6 with QSC PL236, PL3.4, PLX3402, and Crown MT1200. I did not find any to be unpleasant. I find pro amps generally put out what you put in. If you get grainy then look at some other component in the chain. I think almost any pro amp will work better for those speakers than any typical receiver.

Matter of fact, I brought the PL236 to try with the speakers when I auditioned them. The fellow had them hooked up to a large Classe amp and I think was a bit taken by the performance of that small, physically speaking, QSC amp.
 
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Older: Ampzilla, Accupahse P300($$$$), H-K 16, Museatex MTR-100

Newer: Krell KSA-100/200
 
whoaru99 said:
FWIW, I've used my Thiel CS3.6 with QSC PL236, PL3.4, PLX3402, and Crown MT1200. I did not find any to be unpleasant. I find pro amps generally put out what you put in. If you get grainy then look at some other component in the chain. I think almost any pro amp will work better for those speakers than any typical receiver.

Matter of fact, I brought the PL236 to try with the speakers when I auditioned them. The fellow had them hooked up to a large Classe amp and I think was a bit taken by the performance of that small, physically speaking, QSC amp.
Click to expand...

I should add, those pro amps listed would be in addition to a Levinson 23, an Audio Research 100.2, Yamaha M-80, Spectro Acoustics 202, Elan Z660 (LM3886) and probably others I don't immediately recall.

Just thought I'd mention that in case there was any question of diversity.
 
Thanks very much for all the replies. Looks like I have to do some legwork to try and find one of the amps suggested. I do have a couple other questions while I wait for the EQ to be delivered.
Question 1: Will my Kenwood Basic C2 preamp suffice or do I need to look for another preamp?

Question 2: Which one of these vintage receivers will work best with the Thiels until I purchase a power amp? My choices are either a Marantz 4270 (70 watts/ch in 2 channel mode), Pioneer SX-8 (100 watts/ch), Pioneer SX-980 (80 watts/ch), or Yamaha CR-1020 (70 watts/ch).
 
Just a heads up: the CS 3.5 is a great speaker but be careful as Jim initially screwed up a little on the system. He designed a somewhat power hungry speaker using a crossover with gentle rolloff slopes and then made a bass EQ to go with it. The EQ boosts the bass and since the rolloff is gentle quite a bit of energy can make it to the mids. Use the EQ and on some pieces of music you can blow the mids out by be a little heavy handed on the volume. Long after I stopped selling them I seem to recall reading somewhere he later came out with a midrange driver that could handle more power, but I would not swear to it.

Jim and Kathy forbade us, under threat of losing the line, to sell any of their speakers with anything but high end amps, they could live with Cyrus, Audiolab similar stuff. Any contemporary Pioneer/Denon/Yamaha would have been verboten, not sure what they thought of the earlier stuff. Jim really liked the No. 23 (so did I!) but it won't be your cheapest option.

I think they were a little extreme but that generation of Thiel speakers was fairly picky when it came to matching other gear.
 
Thanks Raynald. I heard about the mids issue. I was taking a good look at those today. They look kinda small to be able to handle all these high-current amps. Although, I do completely understand the Thiel folks wanting to sell them with a high end amp. From a marketing perspective, we can't have the Thiels associating with the Pioneers. It's a class thing ya know. Just kidding. Anyway, I just want to make sure whatever I am using was actually designed to drive a 4 ohm load - not an afterthought. I remember back in the early '80s, I had the Ohm distributor leave a set of the Ohm speakers with the Walsh driver in them for me to evaluate. Imagine the expression on his face when he came back and they were connected to the top of the line Sanyo receiver! They did sound good though - even if through one of those "off brand" receivers....

Cheers,
David
 
When I had the 3.5's years ago, I had excellent results with an Adcom GFA555 and even better with a Bryston 4B. The Thiels will certainly reveal any upstream weakness but will offer many hours of bliss in a good set up.
 
McCormack DNA-1 or some nice Odyssey mono amps, Stratos, Khartago are excellent amps and would provide a signal that these speakers deserve. Much better than many of the older main stream gear.
 
Thought I would post an update. I found out the midranges needed to be rebuilt. I know, you are all surprised right? I had Thiel rebuild them and the adjust the bias settings on the equalizer. I can't say enough good things about the great service from Rob at Thiel. I ended up using one of the new Crown Drive Core amps to power them. They really do sound amazing I must say. I can tell by watching the midranges dance on a Donald Fagen DVD Audio disc, that these are not the speakers to crank up AC/DC to concert levels on. They are very revealing speakers as others have noted. I have already started to find some very stark differences in phono cartridges that were not very apparent before. Thanks to all for all the tips and help. I'm not sure I want to keep them yet because of the volume limitation. Although, I could keep them just to have as a reference. Does that make any sense?

Cheers,
David
 
Typically don't "crank" my CS3.6 either and I suppose would consider them my full range reference speakers. So, no, I don't find that odd/unusual if you like the presentation overall. Myself, I like the straightforward/revealing nature.
 
You may find that the clarity reduces your need for volume. I'd keep them and give them a chance for awhile. I'd bet a Hafler DH-220 would be fine with them.

As for having a reference, your statement about revealing cartridge differences kind of answers your question. I would not trade-in such capabilities lightly, especially for an unknown quantity. Happy listening!

:music:
 
I know this is a year late and a dollar short - but here's my experience: They do need power, especially when you go down to 20z with the equalizer as noted. (yes I blew up a pair of midranges too). The sweeter the power the better. I am using a slightly modded (upgraded caps) Adcom GFA 555II (200 wpc) with a passive step attenuator and they sound great, but from my memory of hearing back in the day them with both Classe and Musical Fidelity equipment - believe they are capable of a larger and even more holographic soundstage then the excellent one I am getting. You don't want grainy or bright electronics, they are not forgiving in that regard.
 
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