Amplifiers for TAD Exclusive 2402

[enjoy_the_music]

Hi guys,

So i've got a pair of 2401 twins and 2402's....the 2402's are staying as they best fit my listening space.

I'm looking for any advice regarding amplification.

The crossover frequency is 650hz so i am looking for amplification below this figure.

I have purchased a nice amplifier for the upper bandwidth, the Yamamoto A-02. The Yamamoto A-02 is their top power amp that uses 2a3 or 845 tubes with 4 and 2 watts respectively. I don't believe it is sold outside JP although i could be wrong.

So that leaves me looking for a decent amp on the bass. Now below 650hz things can still be regarded as...tuneful...in my books anyway. So which amp can handle the large woofers on the 2402 and gel nicely with the Yam?

I was looking at a Crown/Amcron K2 and maybe a Citation X-1....obviously looking to spend not so much as Pass labs and so forth. My budget is around 2000-2500$.

Can't wait to get these babies fully set up....although they must pass the girlfriend test first. The largest speakers we had in here before were the venerable and rare Yamaha NSX-10000 Centennials. The 2402's are a fair bit larger still!

Anyway thanks for any comments!

Regards

Richard

[lfh]

The Yamamoto A-02 is their top power amp that uses 2a3 or 845 tubes

/.../

So which amp can handle the large woofers on the 2402 and gel nicely with the Yam?
/.../
My budget is around 2000-2500$.


What tubes will you use?

As to the power amp, I figure at the budget you mention, you can only pick two out of "big, good and new" ;)

How large is your listening room, what is the listening distance, and how loud do you play? Just do the math -- a used Aleph might still fit the bill (finacially and sonically).

If you need more power, look for used Bryston, Perreaux, Electrocompaniet, Dynamic Precision...or perhaps Audio Research to stay (almost) all tube (FET/pentodes).

[scott fitlin]

For those TAD woofers, a Bryston 4B will work nicely.

A Crown K2 will have outstanding punch, and good clean definition.

I like the sound of the Crown K2 on TAD woofers, its a good match, sonically, and powerwise.

If you can find a good Perreaux, thats a great sounding amp, especially in the low end.

[caladois]

Why don't you go for a JDF AUDIO or JMF Audio amplifier. They were design specially for those monitors. With patience you should find a good second hand model.

Regards Stephane

[enjoy_the_music]

Hi guys

Yes i'll have a go...listening distance around 2.5 to 3m...

I guess then the 95db is not as effective at 2.5m away...i'll have to check the frequency charts for the speakers also.

One worry for me is the complexities of biamping and whether the integration between the amplifiers is correct. Thats the main butt of my question really.

Or is it just better to use a large amplifier?

Richard

[lfh]

One worry for me is the complexities of biamping and whether the integration between the amplifiers is correct. Thats the main butt of my question really.

Or is it just better to use a large amplifier?


The main issue is to get the correct transfer functions for the filters. Textbook filters will not do the trick. You didn't mention what crossover you plan to use.

I think we more or less took for granted that you have a factory purpose-built active crossover for the speakers, but maybe this isn't the case? (Or maybe you even plan to use the passive high level filters? I've understood that some audiophiles do this, but then lots of the benefit of biamping is lost.)

I'd say unless you already have an active filter implementation with custom made slopes and EQ for this application, just go with a reasonably big amp for now. (Chances are that forumites (including myself) can help you with a proper active filter design later on, but it's a lot of work in order not to turn your high-end speaker into a "PA system"...)

[enjoy_the_music]

cheers!

Yeah thats what i meant...the TAD's come with TN-2 crossover networks inside.

I'll get the manual, scan and upload an image here.

Also asking John at Bel Canto (who has TAD 2404's i think) about amplification...hopefully a neutral viewpoint!!! :)

Always a bit more complicated than you imagine isnt it...but generally worth the bother :)

[lfh]

So we're talking passive filters... I personally wouldn't "biamp" in this case.


Anyway, I found a pic and some basic specs here:

http://www11.plala.or.jp/teikakakucosme/PIONEER-EXCLUSIVE/etc/tn-2.html

Babelfish translation:

"8 Ohm specifications in order 1 to drive TL-1601a.
It is adopted for Exclusive model2402.

All wiring cords/codes, OFC to the choke coil coil (the oxygen free copper) press joint type wiring and the enlargement gold-plating conversion of the terminal which use introduction and the OFC sleeve, furthermore, thoroughly low design philosophy of leak conversion is penetrated loss conversion such as development and adoption of the high quality condenser low.

It has succeeded in the removal of the inter- leakage which originates in the ground line the LF circuit the to balance circuit by converting.
Furthermore, the HF circuit and the LF circuit are separated completely, in order to be able to pull out the efficiency of each unit which is connected, the design is administered e.g., the turbidity of sound near crossover frequency is erased."


Is the circuit diagram included in the manual?

[lfh]

The starting point for designing active equivalents would typically be to reverse-engineer the passive filters. If you have the circuit diagram (or can figure it out from inspection of the filter), it'd be interesting to run a simulation in SPICE.

Below are some specs I found on the Net:

[lfh]

And the speaker itself (hey you need to change your avatar ;) )

[lfh]

Just in case:

At this level you certainly need a SOTA implementation of the low level crossover in order not to take a quality hit, i.e. "audiophile grade" OP amps or discrete class A. A top notch digital crossover would of course be a nice option: If the SW is "properly designed", it should at least be possible to closely mimic the original voltage drives -- and quite possibly allow for taking it many steps further (time alignment, FIR-based inverse filtering, some SBIR compensation etc).

[enjoy_the_music]

hi,

Ok i have the manual...but its in darned japanese!!!!! :dont-know

I too found some interesting sites where people are playing with the 2402.

http://www.myav.com.tw/forum/showthread.php?pagenumber=3&threadid=268501

http://www008.upp.so-net.ne.jp/tsu-net/audio.htm

They both use a crossover to add further tweeters :)) One of them uses a crossover with the model name ALM HP-105...can't find much info on it.

You're after a scan of the circuit diagrams...doesnt look like there are. All i can see is that the 2402 has seperate boards for the tweet and woofer.

Interestingly both one of the guys and also Air Studio in london, use a Pioneer AX10Ai integrated as it has built in room correction and adjustable crossover slopes!

I have emailed Pioneer for a manual!! :banghead:


ps....you're correct...avatar amended! Hopefully i'll be able to add a photo when i get them set up properly.

[lfh]

OK, please keep us posted about your findings :)

I figure you've pondered various possibilities, but here goes anyway: The changes could be made incrementally from dual amps and passive high level filters towards "proper" biamping:

1. Remove the attenuation from the HP path to make life easier for the little tube amp (no use converting power to heat in the resistors).

2. Possibly introduce a 1:st order HP ahead of the tube amp (e.g. by means of changing a coupling capacitor at the input) at say 1.5 octaves below the crossover frequency, to further slightly simplify the task of the tube amp (no use let it operate on the LP contents only to filter it away afterwards).

3. Replace the LP filter by an active counter part, to make the woofers happy. (You might get away with a simpler implementation than is called for for the HP part.)

4. Finally implement the active HP filter. (Restore the coupling cap (2) to the original value.)

Just an idea.

[enjoy_the_music]

Please understand i'm a novice here :o:

Anyway i will read and re-read what you put down and try to make further headway in my understanding. I have a technical background but in engineering and design, not electronics!

The TN-2 crossovers are discussed here:

http://translate.google.com/translate?u=http%3A%2F%2Fwww11.plala.or.jp%2Fteika kakucosme%2FPIONEER-EXCLUSIVE%2Fetc%2Ftn-2.html&langpair=ja%7Cen&hl=en&ie=UTF-8&oe=UTF-8&prev=%2Flanguage_tools

Also the speakers came with the original twisted pair cable too.

[merlin]

I'm delighted to read that they succeeded in the removal of inter leakage Richard. What next I ask?


PS. The JMF/JDF amps are(were) a good match.

[enjoy_the_music]

Hi M

Know anyone with a JMF amp? Why oh why did i sell the Berning...your words have come back to haunt me!

Reckon a crown k2 will be good? Also looking for some tube euphonics.

R



I'm delighted to read that they succeeded in the removal of inter leakage Richard. What next I ask?


PS. The JMF/JDF amps are(were) a good match.

[merlin]

Actually on the 2401 the Berning would have been stretched as it doesn't like a 4 ohm load with that output impedence, but yes, for the 2402 there is probably no finer option in my opinion. It would make most of the competition sound broken.

The Crown will give you bass oomph. It's not even remotely in the same class as the Berning for other duties. You could of course try a big class A Accuphase.

[enjoy_the_music]

Yes the 2402's are an easier 8ohm load compared to the 2401's. Checking the db/freq charts they seem to suggest that i need quite a few watts to generate the lower registers...maybe 100+

Also looking at stands for the speakers. Maybe some simple cherry blocks from Yamamoto + some spikes on top and bottom...apparently the bottom of the upper horn must be at eye level.

I have a guy in Stuttgart wanting to check the Twin's out...he already has Rey Audio RM8's.

I also bought rather a nice preamp today...just searching for power now.

Check out the charts attached.

R
ps. whats the story with your babies?





Actually on the 2401 the Berning would have been stretched as it doesn't like a 4 ohm load with that output impedence, but yes, for the 2402 there is probably no finer option in my opinion. It would make most of the competition sound broken.

The Crown will give you bass oomph. It's not even remotely in the same class as the Berning for other duties. You could of course try a big class A Accuphase.

[merlin]

Trust me richard, you don't need hundreds of watts on these - just a decent number of good ones.

Are you speaking with Juergen?

[enjoy_the_music]

Hi M

At the moment i have two pairs of Shindo WE 300b (one pair first generation 1980's and the other from 1991, although i prefer the older!)....and a Shindo preamp (Model 77, simple preamp based on Western Electric circuit).

The 300B's as you know put out only 8W...i don't think thats a problem for light jazz music but something more complex like classical i am worried could cause saturation, although the Shindo's output always belies that power rating...also a 4Watt Yamamoto A-02 i currently have with Yamamoto-San changing the transformers for EU 230V types.

I bought a Wavac PR-T1 preamp also as a keeper, so maybe looking for something to power...hmmm.

Juergen...havent spoken yet but yes i think he may be making a visit.

R



Trust me richard, you don't need hundreds of watts on these - just a decent number of good ones.

Are you speaking with Juergen?

[lfh]

Trust me richard, you don't need hundreds of watts on these - just a decent number of good ones.

I second this. Since you posted all the nice graphs, I did some math for you:

As a first approximation we can assume spherical propagation and free field conditions. The attenuation at distance r compared to the level at reference distance r0 is then given by:

A_dB ~ 10*log10(r^2/r0^2) = 20*log10(r/r0)

Let r0 = 1.0 m =>

A_dB(1.0) = 20*log10(1.0) = 0.0 dB
A_dB(2.0) = 20*log10(2.0) = 6.0 dB
A_dB(2.5) = 20*log10(2.5) = 8.0 dB
A_dB(3.0) = 20*log10(3.0) = 9.5 dB
A_dB(4.0) = 20*log10(4.0) = 12.0 dB

In practice the attenuation will be slightly lower (for reasons outside the scope of today ;) )

Similarily, the level at power P vs that of a reference power P0 is by definition:

L_dB == 10*log10(P/P0)

Let P0 = 1.0 W =>

L_dB(0.01) = 10*log10(0.01) = -20 dB
L_dB(0.1) = 10*log10(0.1) = -10 dB
L_dB(1.0) = 10*log10(1.0) = 0 dB
L_dB(10) = 10*log10(10) = 10 dB
L_dB(30) = 10*log10(30) = 15 dB
L_dB(100) = 10*log10(100) = 20 dB

Finally, assumuing that SPL0 is the sensitivity (SPL at 1 W and 1 m), the SPL can be calculated as:

SPL = SPL0 - A_dB + L_dB

Example:

SPL0 = 95 dB
r = 2.5 m
P = 30 W

=>

SPL = 95 - 8 + 15 = 102 dB

Hence, if you listen at "normal" levels (around 80 dB average in my world), a smallish amp will do. However, do get one with low output impedance. The upside of this will be clear once you switch to active crossovers :)

HTH
Fredrik

[enjoy_the_music]

Fredrik, brilliant thanks!

In fact i'd been studying this myself after someone, maybe you!, suggested to do so. Yes, its never a perfect world so you always lose something...i suppose the room itself is the attenuator.

From the calculations you gave my Yamamoto 2A3 amp (4W) at full stretch would provide 93db and the Shindo WE 300b (8W) 96db.

My room is what you might call a small/medium sized studio room.

Speakers are installed tomorrow. I havent got any stands for them so i'm going to cut up some spruce beam (10cm x 10cm) for them to sit on in the meantime, just to get them off the floor.

I guess this is just the tip of the iceberg but it gives me a general idea! Thanks so much for taking the time to help.

Richard

Ps. Low output impedance like a Berning OTL...don't rub it in Fredrik, i sold mine recently and Merlin said i'd regret it...now i am! Any suggestions?

[merlin]

Richard,

my take would be that the 1601a isn't going to like seeing some boutique SET with high output impedence trying to drive it - similarly it won't need a Crown K2 to kick it into life. You need a 70wpc - 100wpc SET effectively - now did you really sell that Berning?

[enjoy_the_music]

Yes i did sell it...its somewhere in the land of kookoo clocks and fine chocolate.

I have Jadis JA-200's but i'm taking them to be repaired on friday (hum problems). They are too big to be keepers.

:applaud: boutique...that's diplomatic.

CAT, Joule, Air Tight and Atma spring to mind. What about ASL Hurricanes?

R



Richard,

my take would be that the 1601a isn't going to like seeing some boutique SET with high output impedence trying to drive it - similarly it won't need a Crown K2 to kick it into life. You need a 70wpc - 100wpc SET effectively - now did you really sell that Berning?

[enjoy_the_music]

And if John Stronczer is using his own Bel Canto gear...why not that.

[enjoy_the_music]

Some photos of my boutique de pede tube amps driving the TAD's...ok for simple music but mushy for anything else.






Actually on the 2401 the Berning would have been stretched as it doesn't like a 4 ohm load with that output impedence, but yes, for the 2402 there is probably no finer option in my opinion. It would make most of the competition sound broken.

The Crown will give you bass oomph. It's not even remotely in the same class as the Berning for other duties. You could of course try a big class A Accuphase.

[dangerisland]

I've owned a pair of 2402s for 4 years. I like the original crossovers and so I use an Audio Research SD135. I'm known for cycling through systems like six packs of beer, but in this case, I've stuck with this setup for over 2 years, basically a millennia. I find myself looking only for source improvements as this system just plays music. NFS.

[Challenger604]

Some photos of my boutique de pede tube amps driving the TAD's...ok for simple music but mushy for anything else.

Attention a ton language s'il te plait!

[speakerdave]

I've owned a pair of 2402s for 4 years. I like the original crossovers and so I use an Audio Research SD135. I'm known for cycling through systems like six packs of beer, but in this case, I've stuck with this setup for over 2 years, basically a millennia. I find myself looking only for source improvements as this system just plays music. NFS.

Sounds like the 2350's didn't do what you wanted. You have a solid set of speakers there. Glad you've found the music again.