My impressions of Lonewolf's RWA TEAC and NuForce Ref 9

audiojerry · « **on:** 3 Dec 2005, 09:01 am »

I didn't post this in the Critic's Circle, because it's not really a review. It's just my impressions of the modded TEAC and the NuForce Ref 9. I decided to combine my impressions here because I happened to have both amps at the same time.

Before I say anything about the amps, I wanted to thank Loanwolf for his generosity for allowing me to try the TEAC out with no questions asked and no conditions. Same of Kevin Jones of Next Level Audio who not only granted me an audition, but delivered it personally to my home. Now that's what I call fantastic service. I can highly recommend Next Level to anyone without hesitation.

I'll start with the TEAC.
I was very surprised by its lack of power, which was most noticeable in the bass. I wasn't expecting much, but I've had a 7wpc single ended Cary that had significantly more drive than the Teac. It just doesn't seem to have anything in reserve to handle the lower frequencies with any kind of control on my 87 db ProAc. It reaches the lowest frequencies, but there's no punch. I initially thought it was due to too much volume, although I didn't think I was playing very loudly, but it didn't make any difference if I turned the volume up or down.

The midrange and treble is clear and grain free. I could hear deeply into the music and was able to pick up fine details. This meant it had good resolution. It didn't sound bright. It wasn't dry either, the way many SS amps sound to me. I initially commented that my evaluation would be based on transparency and resolution, but I have to admit that the lack of bottom end control and dynamics kind of spoiled it for me. I think I understand what the ChairGuy was saying:

Quote

I have found that the refined Class D architecture as found in Tripath and JVC gear is my cup o' tea.....it's available at very appealling prices and it does what I need. But the TEAC, with only 30 watts on tap (and probably limited in important current output) in either stock or Red Wine Audio modded guise, just isn't enough to do duty here. As so many of you have found, I think it best suited to single drivers

I'd have to say that with my system, especially my speakers, the TEAC was not a good match.

Nuforce Ref 9
Now that's more like it. Plenty of power and punch. It really opened things up and sounded dynamic instead of anemic. In terms of a sonic signature, it sounded very similar to the TEAC. The resolution of detail and transparency seemed pretty identical to me, except the Nuforce had a little more body. The big difference was in the clearly defined lower frequency notes. No fuzziness or rounding off. There was more life to the music.

But for me, personally, neither amp suited me. I found that I had trouble listening to either after about 45 minutes. It's hard to explain, but I found both amps caused an irritability and made me uncomfortable. I'm not entirely sure why, though. It didn't sound noticeably harsh, etchy, or bright, but I did detect a slight electronic signature in the music. Instruments didn't sound entirely natural, but vocals sounded pretty good to me. But the longer I listened, the more irritable I became.

Has anyone else experienced this?

I never experience this with my Audio Research tube amp, and I never experienced this sensation with the Belles Reference 350A SS amp.
If it weren't for the irritation I was feeling, I thought the Nuforce was an excellent amp, and like I said, TEAC had pretty much the same sonic character, but it obviously requires a much more efficient speaker. If you are not annoyed by any kind of irritability, either of these amps could be a good choice to consider.

Personally, I'd probably be a better candidate for one of Bill Baker's tube creations from Response Audio, though I never heard one.

One more thing - even though it can be used immediately after turning it
on, I thought the TEAC required about 30 minutes of warm up to reach its best sounding potential.

Another thing: Both amps were extremely quiet with almost no noise coming from the speakers when no output signal was feeding it. I did not hear any benefit to the battery power. This is not intended to be critical of anything Vinnie does. I do not know how much his mods improved the performance of the TEAC, or whether an all-battery system would result in a more significant difference.

Thanks again to Lonewolf, Next Level, the ChairGuy, and Vinnie.

tybee · « **Reply #1 on:** 3 Dec 2005, 11:50 am »

Audiojerry,

Having listened to both digital chip amps as well as the larger powered digital amps with a tubed preamp over extended periods of time, I must agree with your observation of listening fatique. Including what I call digital glare, I have had problems taming annoying sibilance with digital amps. Dusty at Channel Islands claims his digital offerings do not exhibit these digital shortcomings. I am hopeful that some on this forum can confirm Dusty's assertion.

For me, I will stay with tubes until digital can be tamed.

JLM · « **Reply #2 on:** 3 Dec 2005, 01:56 pm »

AudioJerry,

I'm stumped by your findings, particularly of the Teac.

I own a Red Wine Audio Clari-T (6 wpc integrated) and run them to Bob Brines FTA-2000 speakers (single 8 Foxtex F200A driver, 89 dB/w/m, 8 ohm, 30 - 20,000 Hz in room, transmission line design). Bass response is good, maximum spls acceptable (to me) for most listening. The system is in a properly designed room (following Cardias) of 8 ft x 13 ft x 21 ft in the perscribed nearfield setup.

IMO the amp must provide a commanding grip on the speaker in order to provide maximum performance and obviously the above combination doesn't do that. So I bought a stock Teac and gave it a very quick tryout, mostly to make sure it worked. Boy did it work! Bass authority was amazing (deep, full, and musical). It reminded me of 8 inch bass drivers in transmission lines I owned 20 years ago. I'm currently waiting on a Squeeze Box so that I'll have volume controls in order to more directly compare the Clari-T and stock Teac.

Are you a bass and/or spl freak? Does your room suck bass? I'm just trying to reconcile what we've each heard (stock vs. RWA Teac and your speakers/room/taste vs. mine).

Freejazz · « **Reply #3 on:** 3 Dec 2005, 03:57 pm »

Tybee,

My opinion is to attest to the fact that Dusty's amps do not demonstrate any of the "digital glare" about which you speak. For many, the Nuforce may be a great choice, but (again, in my opinion) it sounds like you are searching for more of what the D-200s offer.

Here is the link to my post toward that same end below:

http://www.audiocircle.com/index.php?topic=23468.msg207955#207955

Good luck in your quest!

Scott

TheChairGuy · « **Reply #4 on:** 3 Dec 2005, 05:25 pm »

Hey Jerry....great that you had time with the TEAC. Isn't that Loanwolf a great dude

I doubt my listening skills a lot of the time - so it was pleasant to see that you experienced the same major bug-a-boo that I did; no low end to get excited about. It's eerily quiet, and very, very clear, but without a nice, warm thrummy bottom end, it didn't cut it for me.

I didn't find it fatiguing to listen to, however....like the long ago Norh Multi-Amps and AudioSource Amp3 were, for instance. No super amps these were, so I just attributed it to the price point. No, the TEAC was fine to listen to...but without bottom end energy it didn't make the grade for me either.

fyi - I'm 43 in a 12 x 15 x 8-12' room, with a wife and small child. I'm a happy guy - I have no need for buzzsaw bass to get my jollies. The primary speaker that I used in evaluation was a very nice (a terrific Linaeum 360 degree, top-mounted dipole tweeter and rather ordinary Peerless 6" driver in a front ported, 28" tall cabinet) 2 way, Linaeum Tower speaker that's about 87 db efficient and an 6 ohm minimum (easy) drive.

Three cheers for Vinnie....I think he begat a great platform in the TEAC with battery power, but it need additional refinements in the bottom end to take it to superstar status. I don't think it's as far away from that status now - transparency, clarity are amazing - but that bottom end needs work. We are talking about a $600 ($100 TEAC and $500 worth of Vinnie mods) stereo amp now - it has far more virtues already than most of it's $600.00 competition in the marketplace

gongos · « **Reply #5 on:** 3 Dec 2005, 05:36 pm »

I'm a little suprised also by your Teac impressions. I have one w/ a pair of 626r's and the bass response is fantastic. I've had a number of people over, including forum members, and they've all commented on how good the bass sounds. Must have been a really bad match with your speakers.

audiojerry · « **Reply #6 on:** 3 Dec 2005, 06:13 pm »

Quote

Are you a bass and/or spl freak? Does your room suck bass? I'm just trying to reconcile what we've each heard (stock vs. RWA Teac and your speakers/room/taste vs. mine).]

Not at all. I have ProAc Response 2.5's. Small floorstanders with 6.5" Scanspeak midbass drivers. The bass is very taught down to about 40hz, but my room does suck up the bass. Others have noted and mentioned this about by room. It's very heavily dampened. Even so, my comments are in relation to the bass that other amps provide in the same space. The bass of the Teac does reach the lowest frequencies my speakers can deliver, but the bass is very loose. It lacks definition and punch.

Both amps are exceptionally clear. I found vocal sibilance to be excellent.

Some amps are fatiguing because they are too bright or harsh, and it's easy to identify the source of the annoyance. With both the Teac and NuForce, it wasn't really obvious. All I know is that over time, it became increasingly irritating. I could not get involved in the music at all. I felt compelled to just shut the system down. This never happens to me on Friday nights.

I kind of figured this would stir up some controversy. I didn't have any agenda, other than my ongoing search for more economical amplificaiton.
But go ahead and berate me if you like.

Let me have it.

Vinnie R. · « **Reply #7 on:** 3 Dec 2005, 06:26 pm »

Hi All,

First, another big "thank you" to Audiojerry for posting his impressions of the RWA Teac.

I, too, am surprised by both TheChairGuy and AudioJerry's comments about wanting more bass. I think just about every customer who has sent me feedback about their modded Teac stated that it has much more solid and punchy bass that the stock Teac. Still, there are going to be cases where 30 watts are just not enough for certain speakers, rooms, listening preferences.

I'm starting to wonder about a couple of things

:

1) Is there something wrong with that unit?

It was brand new and I pretty much only had it playing at RMAF and then it was purchased by LoneWolf, who mentioned that it will be sent to me to check out before he receives it. It seemed to work fine at RMAF, but the comments about lack of bass do have me concerned. This is certainly not a bass shy amp, but comparted to a 100 watt amp (ex. Nuforce), maybe it is with lesser efficient speakers.

2) Maybe its 30 watts are just not enough for 87dB speakers? The thing is that I have received feedback from Clari-T customers with 87dB speakers and say it drives them very well (of course, up to a point). Room size, listening preferences (in volume), etc. can be a big parts of it too.

3) Maybe these lower powered Tripath amps are just better suited for crossoverless speakers? I wouldn't think this is the case with the Teac. I have not found its 30 watt rating to be "fluffed up" in any way. To all the stock Teac owners out there, what is your take on this?

Quote from: TheChairGuy

Three cheers for Vinnie....I think he begat a great platform in the TEAC with battery power, but it need additional refinements in the bottom end to take it to superstar status. I don't think it's as far away from that status now - transparency, clarity are amazing - but that bottom end needs work. We are talking about a $600 ($100 TEAC and $500 worth of Vinnie mods) stereo amp now - it has far more virtues already than most of it's $600.00 competition in the marketplace ...

I need to thank you all again for your feedback, as this is VERY valuable to me in the design of my new 30-watt version of the Clari-T. I'm pretty sure I will sell them fully modded, with big ol' SLA's (for long play time), and will have to test it with less efficient speakers and compare the bass to higher powered amps to get a sense of its bass output abillities. I have decided that it is also essential that I include an indicator for the battery voltage (to make sure that it is operating in the intended voltage range).
The biggest goal of the Clari-T Signature 30 is for it to reach out to customers that can't get away with 6-watts of power, and for it to sound even better than the modded Clari-T. Oh yeah, I need to keep it at a competitive price point too

. I want to raise the bar high, and as things progress I will post updates on my circle.

Thanks again to everyone for your feedback,

Vinnie R. · « **Reply #8 on:** 3 Dec 2005, 06:37 pm »

Quote from: audiojerry

I kind of figured this would stir up some controversy. I didn't have any agenda, other than my ongoing search for more economical amplificaiton.
But go ahead and berate me if you like. Let me have it. ...

Jerry,

I am very certain that you do NOT have any hidden agenda, and just like ChairGuy, I appreciate you telling it as it is.

Based on all the feedback that I have received from the modded Teac, I can also see why there are going to be some very curious members who are not sure why things didn't work out so well for you and John (in the bass department). Still, the fact is that is didn't work out with your system and that is the bottom line and we have to respect that...I do.

I just hope it isn't something stupid like a charger that isn't properly charging the batteries or a dud SLA battery. This is another reason why I really need to include a voltage indicator on my future battery-powered products...just to make sure that everything is working out.

On a side note, when the amp is OFF and the charger cable is plugged into the amp, one can unplug the charger from the AC receptacle and use a voltmeter to test the battery voltage, which will be across the + and - terminals of the battery charger (where the cable meets with the charger). It bes' be 12V or higher! (remember, the two SLAs are in parallel during charge mode)

KJ · « **Reply #9 on:** 3 Dec 2005, 06:37 pm »

Jerry,

Glad we could help you out! Looking at the time of your post, it looks like you were doing some heavy duty auditioning!

Quote

But go ahead and berate me if you like.

Everyone has their personal preferences, so I don't see any reason to berate you.

I wonder if a tubed source might have been a better fit for your tastes. We often use the Jolida JD100a for Nuforce demos which provides a more warm and mellow sound that some prefer. It also really kicks up the bass. System synergy is everything, and I think matching equipment to one's tastes is what makes this hobby so much fun and challenging.

-KJ

Jon L · « **Reply #10 on:** 3 Dec 2005, 09:49 pm »

Vinnie, ProAC Response 2.5 is claimed to be 86dB sensitive, but it measures to be 83dB sensitive.

http://stereophile.com/floorloudspeakers/196proac/index3.html

I don't know what all the puzzlement is about. Teac, modded or not, simply had no business being connected to these speakers.

JLM · « **Reply #11 on:** 4 Dec 2005, 02:43 am »

AudioJerry,

I respect you as knowledgable and as a pillar in the AC community.

If the ProAc are really 83 dB/w/m with rated bass only to 40 Hz in a room that does suck bass it pretty much explains why the Teac would have problems. I've got about the same speaker efficiency plus gain total here and a bigger room quickly shows the combinations limitations.

And maybe Vinnie is on to something with the single driver thought. After all, no crossover means an active design (with all it's advantages) by default.

lonewolfny42 · « **Reply #12 on:** 4 Dec 2005, 03:19 am »

Thank you Jerry for posting your comments on the RW Teac....

Chris[/list:u]

TheChairGuy · « **Reply #13 on:** 4 Dec 2005, 03:39 am »

Yep, I had the TEAC hooked up with the A8 for a time.....and didn't perceive any bottom end insufficiency there. I shoulda' mentioned that earlier

But certainly did with 87 db Linaeums......and it simply could not fully drive the 86 db Magnepan MMG's. Magnepan recommends, however, a minimum of 50 watts...so it was not a surprise.

rustydoglim · « **Reply #14 on:** 4 Dec 2005, 04:09 am »

Jerry, and others who are auditioning NuForce amp:
We recommend that you try it with the standard Ref 9 power cord and use a Brick Wall audio surge protector (which has good EMI/RFI filter). It is a cheap solution to prevent the switching noise from affecting your upstream devices through the AC ground. NuForce is very sensitive to power cord and wires so I think it is entirely possible to get rid of the listening fatigue that you experience. This is very interesting because some other people mmakshak for example, claimed to love Nuforce sound so much that he listened for days none stop.

So this is an interesting research that we'll like to persue about why a few people (in the very minority) have listening fatigue. Are they being affected by HF noise, wide bandwidth (>50Khz) or something else?

Jerry, if you really like NuForce but the only thing that bother you is the listening fatigue, contact us directly and we'll like to experiement with you

.

JeffB · « **Reply #15 on:** 4 Dec 2005, 04:20 am »

I currently have a clari-t, a JVC D201 and a pair of Athena AS-F2.2s.
The Athena's are 93db sensitivity at 8 ohms with one tweeter and two 8" drivers. The tweeter is crossed over at 2k Hz. Bass is rated to down to 35 Hz, but I have an in room response down to 30 Hz.

The JVC is rated 100W x 7. Although the rating is restricted on the front channels from 40Hz to 20kHz. I think on the other channels it is only rated at 1kHz. It does output from 20Hz to 20kHz, it's power is just not rated across the full frequency range.

The clari-t is about 6W into 8ohms.

The bass is much stronger and tighter with the JVC. The JVC also seems to flesh out the midrange better. It really seems to be an issue of power. Volume does not really seem to be a factor here. The JVC has more control over the speakers at all volume levels. The clari-t plays plenty loud enough with the Athenas.

I also had on loan a NAD c270 which is 120W into 8 ohms. This seemed to create an even punchier sound than the JVC, but with less control over the bass. The bass seemed looser. The NAD had sweeter highs, more punch and less bass control than the JVC.

I have tried the clari-t with Zu Druids(101db). I didn't notice a lack of bass with this combination. However, I did not have the JVC at the time to compare. I wish I did.

I am still looking for a match for the clari-t. Either more sensitivity, no cross-over or some other magical ingredient.

audiojerry · « **Reply #16 on:** 4 Dec 2005, 08:05 am »

Quote from: Jon L

Vinnie, ProAC Response 2.5 is claimed to be 86dB sensitive, but it measures to be 83dB sensitive. I don't know what all the puzzlement is about. Teac, modded or not, simply had no business being connected to these speakers.

That may be the whole problem. I didn't realize the ProAc's were that inefficient. ProAc's have generally been regarded to work well with tube amps, and I thought the recommended amplification started at 30wpc, but I don't have the owner's manual to confirm. I wish I had a set of more efficient speakers. When I had the Cary 300b, it may have had output up to 11wpc, but it produced pretty good bass with ProAc Tab Signatures. I don't recall the sensitivity of the Tabs.

Still, it doesn't explain the listening fatigue with either amp. I was powering the NuForce through the cords supplied to me by KJ - don't know what they are. They were plugged into one of my isolation transformers.

I'm always willing to be experimented on, Jason, as long as you don't cut me open

Thanks for the offer, but I believe Next Level needs to send the demo's to another customer.

Lonewolf, I was auditioning the TEAC primarily with instrumental jazz - always acoustic bass. I also listened to some Madeline Peyroux, Alison Krauss and Union Station, and Van Cliburn playing Rachmaninoff Piano Concerto #2.

Thanks for all the good feedback.

Vinnie R. · « **Reply #17 on:** 4 Dec 2005, 05:22 pm »

Quote from: Jon L

Vinnie, ProAC Response 2.5 is claimed to be 86dB sensitive, but it measures to be 83dB sensitive.

http://stereophile.com/floorloudspeakers/196proac/index3.html

I don't know what all the puzzlement is about. Teac, modded or not, simply had no business being connected to these speakers.

Hi Jon L,

Thanks for the info!

If they are measured to be 83dB sensitive, I'd have to say that 30 watts is certainly on the low side if you are looking for some decent bottom end. With 83dB speakers, I'd want at least a 100wpc amp to do some justice to the music

Hi Audiojerry,

I forgot to ask what source and preamp were you using? Besides the low-efficiency speakers, it could have also not been the the best synergy with the source and pre...

Thanks for sending it back to me. I'll check it out and send to the Lonewolf.

Regards,

audiojerry · « **Reply #18 on:** 4 Dec 2005, 06:30 pm »

Source is a Classe CDP-1 dedicated transport to a Modwright P-3A dac.
Pre is a tubed SAS Audio 10A, dual volume controls, no remote.
Wire is Ridge Street Poiema silver wire.

lonewolfny42 · « **Reply #19 on:** 4 Dec 2005, 06:49 pm »

Thanks guys !!!!