First review of Spark is in - and I couldn’t be happier!!

G Georgopoulos · « **Reply #20 on:** 26 Feb 2016, 02:53 am »

oh ok, thanks!

Zero ,your video reviews are very good!,all the best mate...

Wind Chaser · « **Reply #21 on:** 26 Feb 2016, 06:52 am »

Quote from: JLM on 26 Feb 2016, 12:23 am

Careful, I had a 7 wpc driving 91 dB/w/m speakers with similar taste listening near-field in a 8ft x 13ft x 21ft room. It was enough, but moving up to 40 wpc turned my speakers from polite dinner guests into NFL linebackers in tuxedos.

Ah, but come dinner time, would you rather host polite dinner guests ...or NFL line backers?

About 5 years I had an Ampino (similar power output to the Spark) and oh gosh, it could put a lot of pretentious more powerful amps out to pasture. It was ridiculously musical, engaging and satisfying to hear music flow out of it, that is... within its limitations.

Like all flea amps (and I've had a few... 2A3, 300b, EL84, SV83 and a TPA3116 etc) partnering is very important. My head tells me I need at least 60 watts (x2) but the Spark is pulling on my heart strings. Great sound on a shoestring is very auspicious and satisfying.

Perhaps to some extent one could compensate by tasking the bottom end to augmentation?

JLM · « **Reply #22 on:** 26 Feb 2016, 01:10 pm »

Yes, off loading bass to a sub (or just using speakers that don't do deep bass) would help.

And yes again, watts on paper don't translate into real world watts. My 7 wpc Tripath kicked tiny tube amp butt on my 25 - 20,000 Hz 91 dB/w/m 8 ohm speakers. They were pukey thin sounding compared to my Tripath. But more watts provided more resolution overall and fuller/tighter bass. That beefy power supply should help provide a good grip (within it's limits of course).

Zero · « **Reply #23 on:** 26 Feb 2016, 04:24 pm »

Thanks Georgo.

Audiovista · « **Reply #24 on:** 28 Feb 2016, 09:48 pm »

Quote from: JLM on 26 Feb 2016, 01:10 pm

Yes, off loading bass to a sub (or just using speakers that don't do deep bass) would help.

And yes again, watts on paper don't translate into real world watts. My 7 wpc Tripath kicked tiny tube amp butt on my 25 - 20,000 Hz 91 dB/w/m 8 ohm speakers. They were pukey thin sounding compared to my Tripath. But more watts provided more resolution overall and fuller/tighter bass. That beefy power supply should help provide a good grip (within it's limits of course).

Agreed. A "problem" with low power tube amps is in the tiny output transformers (relatively speaking) . Solid state amplifiers don't have the same problem. Even class D amplifiers have mosfets which are rated much higher than amplifier's maximum output current, and output filters have fairly low impedance due to the high switching frequencies. Not to mention massive amounts of negative feedback. Still, small tube amps can bring a lot of joy, when carefully paired with efficient speakers.

BTW - I overcame the transformer issue with my personal 2A3 tube amp (3.5Wpc), by using massively oversized transformers, which would be comfortable in a 300B configuration as well. But, two 8 pound output transformers, and another (heavier) one for power supply, do not yield lightweight and inexpensive tube amp. On the other hand... it cannot be beat by anything in the similar power range (<10W) and priced up to $20k (it did go through three months of testing by third parties

).

Audiovista · « **Reply #25 on:** 17 Mar 2017, 06:10 pm »

Somewhat surprising feedback from a customer in Germany: he borrowed Spark from his friend to try with his ATC SCM7 speakers (http://atcloudspeakers.co.uk/hi-fi/loudspeakers/entry-series/scm7-mk3/). Shortly after, he bought his own Spark.

What is surprising is that SCM7 have low sensitivity (84dB @ 1W, 1m) and seem to require high power (spec is 75-300W). Yet, the customer also tested several high power amplifiers and did not find them satisfying for jazz and chamber music. I have always thought that 87-88dB is practical lower limit for Spark and I am glad that this assumption has been successfully challenged.

Russell Dawkins · « **Reply #26 on:** 17 Mar 2017, 07:00 pm »

Quote from: Audiovista on 17 Mar 2017, 06:10 pm

Somewhat surprising feedback from a customer in Germany: he borrowed Spark from his friend to try with his ATC SCM7 speakers (http://atcloudspeakers.co.uk/hi-fi/loudspeakers/entry-series/scm7-mk3/). Shortly after, he bought his own Spark.

What is surprising is that SCM7 have low sensitivity (84dB @ 1W, 1m) and seem to require high power (spec is 75-300W). Yet, the customer also tested several high power amplifiers and did not find them satisfying for jazz and chamber music. I have always thought that 87-88dB is practical lower limit for Spark and I am glad that this assumption has been successfully challenged.

This fits with what I was advising a young audiophile just yesterday—take amplifier performance figures with a huge pinch of salt. Years ago I had the experience of a 35 WPC Mission Cyrus 1 amp performing as though it was more powerful than a (nominal) 120WPC NAD amp, in that I could play my system louder before it became objectionable.

According to Antony Michaelson of Musical Fidelity we are operating our amplifiers into minor clipping more regularly than we realize. According to a survey done by HiFi News ages ago, one of the few measurable amplifier performance characteristics associated with what is perceived as good sound is clipping recovery behaviour—some (marginally stable) amps get upset and recover erratically and relatively slowly and other amps recover quickly and cleanly. The latter tend to sound better.

Maybe the Spark has good clipping recovery characteristics, since it probably was clipping a little, driving those ATCs.

groovybassist · « **Reply #27 on:** 17 Mar 2017, 08:10 pm »

Interesting timing on this user's experience with low sensitivity speakers - I'm going through something similar the last day or so.

My secondary speakers are a set of Harbeth P3ESRs, which I listen to every once in a while. With my main amp (a Karan KA-I180 Mk 2), I could never really get along with the Harbeth's. You would imagine an amp like that could make anything sound good. All the audiophile boxes would be ticked off when using the Karan/P3 combo - clarity, texture, imaging, etc., but I just couldn't get emotionally involved in the music. I always wanted to just take the P3s out.

Enter the Spark. I've had the Spark for a while and was using it happily in my office system, which ended up being dismantled, leaving the Spark idle. Completely on a whim, I decided to try the Spark with the P3s and damn - it's way more enjoyable to listen to than the Karan/P3 combo! I'm sure all the audiophile stuff is better represented by the Karan, but there's absolutely no doubt in my mind that the Spark/P3 combo communicates the emotion in a performance WAY better. I feel like I've finally understood and gotten the measure of the P3s in my system for the first time. I'm literally listening to this combo right now and feeling like I need to check out Harbeth's more expensive offerings.

Sometimes unexpected pairings yield better results. Definitely the case with the Spark and P3s. Kudos to Boris on the Spark. The fact such an unassuming, inexpensive amp can run comfortably with much more expensive, inefficient speakers should open people's minds to the possibilities in "unconventional" pairings.

bacobits1 · « **Reply #28 on:** 17 Mar 2017, 08:20 pm »

Indeed, I thought the little Spark sounded very good here too, 4 Ohm 91db Ushers. Especially after I left it on. Comparing it to a Pathos Classic One MKII. Surprised the hell out of me, the presentation that is. It kept up fine. Plug it with an iFi itube 2 .....................................

Everything on my front end has been changed now but I would expect it to sound better. AND, ya never know how things will match up in your system. Somtimes we get hung up on the price judging things.
Ahhhhh no remote LOL! I have gotten very lazy with the volume control, gotta have remote, but I know there are ways around that reasonably too.
For $350 cool stuff

.

Zero · « **Reply #29 on:** 17 Mar 2017, 10:43 pm »

Still have my Spark. Still loving it. The iTube 2 recommendation is spot the heck on. A great , compact, budget friendly setup!

WireNut · « **Reply #30 on:** 4 Jan 2018, 12:25 am »

Boris, How bout a Spark without a power amp section, or the option to by-pass the power amp section and use the spark
as a preamp only?

Audiovista · « **Reply #31 on:** 4 Jan 2018, 11:46 am »

Hi Steve,

Spark without power amp would end up being just a passive preamp. Spark-T will be little more than just an amplifier, but I'll take a look if the power amp bypass can be incorporated without penalties. Do you think that the feature makes sense for a desktop amplifier (I think of Spark-T as a desktop amplifier, but it can be used with any sensitive speakers, pretty much same as the solid-state Spark)?

The preamp that I mentioned in the other post (http://www.audiocircle.com/index.php?topic=149034.new#new) will have an iteration with tube buffer. When I figure out all the details maybe that becomes a stand alone preamp. Lot of testing will be needed... looking forward to it

Audiovista · « **Reply #32 on:** 19 Jan 2018, 09:07 pm »

The new review just published by Steve Guttenberg. Short and sweet! It made my day (and much more)!

https://youtu.be/lSRRqN_kIvA

timmy · « **Reply #33 on:** 3 Sep 2018, 03:47 pm »

Is there a break in period for the amplifier? Does it sound better after being played for a certain period of time (warm up)?

Audiovista · « **Reply #34 on:** 4 Sep 2018, 07:19 pm »

Twenty hours should be enough for initial burn in. On a daily basis, 15-20 minutes of warm up is sufficient.

auskip07 · « **Reply #35 on:** 9 Jan 2019, 08:42 pm »

Got my spark in yesterday and am very impressed by it. I chose ELAC debut 2 B6.2 and it pushes them well and i haven't even approached the breakin. (half way volume) Im no audiophile but for the cost of the setup i dont think it can be beat by much.

Audiovista · « **Reply #36 on:** 3 Oct 2019, 01:52 pm »

Still going strong!!

Audiophiliac's "Believe it: $1,250 (or less) can buy a complete audiophile system"

Spark starts at 11:40

https://youtu.be/Fdb8wLd73Tg

Audiovista · « **Reply #37 on:** 20 Oct 2019, 12:12 pm »

https://youtu.be/2Q2VsdedGMs

rollo · « **Reply #38 on:** 20 Oct 2019, 04:12 pm »

Boris that Spark is catching fire. Good luck. Another gem from Boris.

charles

Audiovista · « **Reply #39 on:** 20 Oct 2019, 11:55 pm »

Thank you Charles!

Yes, the Spark is doing well, worldwide - we even sold about dozen units in China! I’m psyched about that.

Best,
Boris