SET amp under $3000

AliG · « **on:** 22 Oct 2008, 04:10 am »

Can anyone pls provide a shortlist of good SET amps under $3000??

I'm going to use it for my upcoming new speakers, which looks like the one in the picture, but mine has ribbon tweeters

From the published technical specs:

Frequency Response: 30-30kHz +/- 2 dB
Nominal Impedance: 8 ohms.
Sensitivity: 93 dB/2.83V/Meter
Crossover: 450Hz Second Order Acoustic In-Phase Linkwitz-Riley (Woofer to Midrange)
and 2.5kHz Fourth Order Acoustic In-Phase Linkwitz-Riley (Midrange to Tweeter)

JimJ · « **Reply #1 on:** 22 Oct 2008, 05:14 am »

Are you wanting a stereo amp or monoblocks or either?

I'd be looking at 300Bs, minimum. Maybe if you were actively bi-amping and not dealing with passive crossovers you could run less, but I'd feel comfortable with 8 watts or more on those speakers. There are a ton of good 300B SET designs out there, I'd probably be gravitating towards Bottlehead's amps; I really liked the Foreplay 2 preamp I had from them.

The 'peekas are quite pretty, gives me an idea or two for a DIY project

lonewolfny42 · « **Reply #2 on:** 22 Oct 2008, 05:36 am »

Surf's up Barry....

Good luck with the new speakers....

So.....a little over budget....

http://www.audiogon.com/cgi-bin/cls.pl?ampstube&1228750198&/Dehavilland-Aries-845---G-Mono

Here's the info.....

Also....keep you eyes open for a KR Audio amp....not many come up for sale used....but they make some excellent amps.

AliG · « **Reply #3 on:** 22 Oct 2008, 05:40 am »

Darn!!!

I've totally forgotten to check out Dehavilland room at RMAF08!!!

Quote from: lonewolfny42 on 22 Oct 2008, 05:36 am

Surf's up Barry....

Good luck with the new speakers....

So.....a little over budget....

http://www.audiogon.com/cgi-bin/cls.pl?ampstube&1228750198&/Dehavilland-Aries-845---G-Mono

Here's the info.....

Also....keep you eyes open for a KR Audio amp....not many come up for sale used....but they make some excellent amps.

lonewolfny42 · « **Reply #4 on:** 22 Oct 2008, 05:42 am »

Quote

I've totally forgotten to check out Dehavilland room at RMAF08!!!

No need....it always sounds good...

Quote

"deHavilland Electronics with Wilson Benesch speakers,

the room we revisited the most. Sound to die for."

John Zurek, Positive Feedback RMAF 2008 Show Report

fsimms · « **Reply #5 on:** 22 Oct 2008, 11:03 am »

Since you are going to be using the speakers with a Dodd preamp which has tubes, why not consider a nice solid state amp. As you know I like my McCormack 225 amp. The McCormack 125 is supposed to be a killer and sound like mine. I can always bring my amp over so you can try it before you buy an amp.

Bob

woodsyi · « **Reply #6 on:** 22 Oct 2008, 12:53 pm »

Barry,

One word -- biamp.

DaveC113 · « **Reply #7 on:** 22 Oct 2008, 01:10 pm »

An 845 SET is closer to 20 wpc... much better. Not cheap though.

Dave

gsm18439 · « **Reply #8 on:** 22 Oct 2008, 01:51 pm »

EAR 859 or 869

AliG · « **Reply #9 on:** 22 Oct 2008, 02:09 pm »

Errr...no no.. this is a completely different system. I will use my modified TACT 2.0S as the preamp.

The Dodd preamp will sit permanently with the HT3.

Quote from: fsimms on 22 Oct 2008, 11:03 am

Since you are going to be using the speakers with a Dodd preamp which has tubes, why not consider a nice solid state amp. As you know I like my McCormack 225 amp. The McCormack 125 is supposed to be a killer and sound like mine. I can always bring my amp over so you can try it before you buy an amp.

Bob

JoshK · « **Reply #10 on:** 22 Oct 2008, 02:10 pm »

My humble dos pence,

#1 biamp as woodsyi says. Seriously, it will make a significant difference in the performance of the SET amp to not have to drive the bass woofer. Damping factor which is needed for woofers is not the strength of SET amps. Here you can really make your money go a lot further if you use a beefy SS amp on the woofer, then a more attainable medium powered SET amp can be used to best results.

#2 it is easier to make a good quality lower powered SET amp then a higher powered one. Price, complexity both go up exponentially with power. Also 20w SET amp typically have extreme voltages (900+) in the power supply making them a risk if you have small children/pets.

#3 IMO, there is no rocket science to SET amps. The best designs are typically simplistic, the technology having been around since the '30s. Often times the hobbiest built amp that they sell, as a hobby. This is probably the best price/perf, not having to pay for overhead business costs, dealer markups, etc.

Names of such hobbiest don't come to mind off hand, but I've seen many of their offerings on A'gon. Their designs look sound and unlike many marketeer's offerings, there is transparency to their designs, so any technician can work on the amps. Most often the designs are point to point which make maintenance easier as well as less needed.

Bottlehead is also a good value proposition. Their designs are very well thought out. You aren't paying extravagant markups for fancy ads in hi-fi rags and distribution channels. They use great iron (Magnequest), which is the biggest component to performance in a SET amp.

JoshK · « **Reply #11 on:** 22 Oct 2008, 02:12 pm »

Quote from: gsm18439 on 22 Oct 2008, 01:51 pm

EAR 859 or 869

Those are supposedly fantastic sounding amps. Classics and uniformly praised.

fsimms · « **Reply #12 on:** 22 Oct 2008, 02:17 pm »

Quote

Errr...no no.. this is a completely different system. I will use my modified TACT 2.0S as the preamp.

The Dodd preamp will sit permanently with the HT3

Then I agree with you. Get tubes!

Bob

AliG · « **Reply #13 on:** 22 Oct 2008, 02:37 pm »

Can someone explain to me how do I bi-amp?

Let's assume that I now have a SET amp, and a SS amp. Now what, do I need a preamp that will send the mid-high signal to the SET, and then the bass signal to the SS amp?

what kind of preamp will do that?

macrojack · « **Reply #14 on:** 22 Oct 2008, 02:54 pm »

The signal is divided after the preamp and before your amplifiers. If your existing passive crossover networks are set up for biamplification, it's a plug and play situation. If not, you will need a passive network designed specifically for your cabinets and drivers or an electronic crossover carefully calibrated to the same parameters. In either case, you will need someone else's skills to optimize the crossover points, slopes and gain matching. It requires instruments and experimentation.

woodsyi · « **Reply #15 on:** 22 Oct 2008, 02:57 pm »

I thought TACT had crossover functions, no? You are already in digital domain in Tact. So, you can use any of the digital active x-overs like the Behringer DCX unit to handle that chore but you would lose the DAC and output sections of the Tact preamp. I know you put some money into those sections.

BTW, active x-over work best when you take the passive out of the loop. Check with your speaker manufacturer to see if this is feasible. Otherwise you may have to use passive biamping which will bring level matching into the equation.

I use an analog active x-over from Marchand since I don't want my vinyl signal going through the AD/DA conversions. Now, if you have binding posts for each driver, I can lend you a 3-way active crossover for triamping....

JoshK · « **Reply #16 on:** 22 Oct 2008, 02:57 pm »

The easiest solution is to passively biamp. If you have two outputs from your TACT preamp, run one to the SET amp, and one to the SS amp. If you don't have two outputs, use a Y cable to make two. Then hookup your SET amp to the upper mid/tweeter binding posts and the SS amp to the woofer binding posts. The passive crossover does the splitting for you.

The only thing then to account for is the difference in (voltage) sensitivity of the two amps. Ideally, you can have your SET amp made to match the sensitivity of the SS amp you choose. SS amps typically have lower sensitivity than tube amps. This means you would otherwise need to put an attenuator in front of the tube amp to match the sensitivities. The closer the sensitivities are to eachother, the less attenuation needed by the more sensitive amp, which is a good thing IMO. You really don't want to amplify just to throw it away on a resistor to ground.

The specs to look for is input sensitivity for the two amps.

woodsyi · « **Reply #17 on:** 22 Oct 2008, 03:05 pm »

The level matching is what killed the passive biamping for me. I hate the idea of putting a muzzle on the tube amp for the mid/highs but I tried. I didn't like it. If you are go passive, find a SS amp with high output voltage so you don't have to attenuate the tube amp.

AliG · « **Reply #18 on:** 22 Oct 2008, 03:06 pm »

The TACT only has one output. So I'll have to find an interconnects that will split into 2 pairs of L/R.

So Woodsyi, are you doing active bi-amping now?

miklorsmith · « **Reply #19 on:** 22 Oct 2008, 03:10 pm »

Behringer A500 - check this bad boy out:

I replaced a Crown K2 at 500 wpc with two of these set up right next to the speakers (12" speaker cables). They drive my 4x10"x2 bass arrays much better, I believe because of the short speaker cables. They have attenuators and you should be able to keep the attenuation out of the tube amp (BOO) in favor of tailoring with these.

Best part? CHEAP! I got mine for $170 ea. delivered. I'm only using them to about 100 hz but I think they'd be fine to 450. Also, check the woofer impedance curve. Behringer recommends an 8 ohm load when running these bridged.

I haven't dealt with these guys but here's a great deal - B-stock at $129 ea:

http://www.audiolines.com/product.php?productid=12906

Correct me if I'm wrong, but biamping won't take the XO circuit out of the equation. You don't need an outboard XO to split the signal from the TacT, just a Y-splitter like Joshk said.

Wanna get totally crazy? You could dump the TacT and replace with a parametric EQ on the bass circuit. You could go source direct or have any flavor of preamp. Nahhh, that's just nuts.