[Horizons]

have you checked out the modded teacs, used as monoblocks?

talk to mcgxsr (mark, i hate your handle! NOT ONE VOWEL!)
he has been using two teacs for a while, tho i forget what eventually he decided on.

Yes, I have read the information on the Teacs but at 30 WPC, and after already trying digital receivers with much higher power, I am not terribly excited about trying a 30 watt amp on my big 4 ohm planers.

I am hoping that with the Panny XR70 in biamp mode I will be delivering around 100W to each leg of the crossover and this might put the power issue over the top.

The problem is that once you have heard Maggies driven by a high current amp, anything else sounds thin. I am an audiophile who likes his sound leaning on the fat as opposed to thin side.

[mcgsxr]

My apologies to sleepkyng for choosing a handle with NO Vowels!

As for the Teac driving the Maggies - no idea - these little amps push my 4 ohm Totems fine, but the Maggies are reknowned for being a really tough load - I would guess that power supply mods would be required, at least...

How sensitive are the Maggies anyway?

Oh, and since it has been so long since I had all my gear in the same place, I forget what I eventually decided on!  Actually, I am waiting for the mods to be all finished, then I will be able to determine what direction to go, for my hybrid 2 channel/HT system.

[Red Dragon Audio]

Horizons,

I wonder if a custom autoformer would help your situation?

I am working with a custom winding company to get a pair of  2x autoformers out here to test with my XR45.  Mostly for sound quality as I have read another post about a fellow who found his Zero Autoformers set on the 2x setting, improved the sound greatly.

I wonder if it would help with your 1.6's?

[Zero]

mcgsxr,

What totems are you driving?  I just got my TEAC today, and have been running it on the Tabus and the Sttafs.

[Wayne1]

Here is a quick shot of the innards of the SA-XR70.

It is using the same amp board as the SA-XR50.

The power supply board is just about the same as the 50, too. It is not similar to the 45.

There is an extra relay on the B speaker terminals. I believe that is for the Bi-amp circuit. I will have to spend some time with the service manual to work out the mod for that section.

[Red Dragon Audio]

Wayne,

Have you had time to hook it up and listen to it bone stock? If so,what are your initial thoughts on the sound of the 70 vs. the 45 and the 50?

[mcgsxr]

A6M-ZERO, I have a set of the Rokk, a 4 ohm, 86db sensitive 2 way, roughly replaced by the Rainmaker in the lineup, I believe.

Hit my "Teac - Initial Thoughts" post with some details as you break in the Teac, I look forward to hearing about it.

That Panny 70 certainly looks interesting...

[ABEX]

Besides getting rid of the tangle of wires for hookup is there any sonic bene to purchasing the 70 unit with HDMI Inputs?

[Wayne1]

I hooked up the 70 last night and ran it all night playing our local jazz station. It sounds similar to the other receivers at this stage. It does seem a little weak in the low end, right now.

Any more comments about the sound and mods will be made on the BOLDER Cable Circle. The owner of this receiver has already started a thread there


ABEX,

You may want to take a look at what Jon Risch has to say about HDMI

The digital audio portion will still have all the same issues the digital cables have now: bandwidth issues, noise pickup, signal distortions, all leading to various forms and levels of jitter.
See:
http://www.geocities.com/jonrisch/jitter.htm

Only now, the digital video will have jitter artifacts to be dealt with too.

In fact, since the video and audio are transmitted over the same lines, there is the strong likely hood that the digital audio signal will be contaminated to one extent or another by the video signals, as per the above referenced article on jitter. The addition of this higher data rate digital video signal only measn the amount of RFI that is broadcast by the HDMI interface and send/receive circuits, and the amount of PS sing-song, will be much greater than what goes on with the existing audio only SP/DIF interface.

So in point of fact, you may be lamenting "the good old days" of SP/DIF, since the HDMI might be even worse for audio (and video).

All they really care about is Joe HT hooking up their HT system as painlessly as possible, and 'good enough' is the watchword. Oh, and the fact that the HDMI cabling system incorporates all the full-blown anti-copying techniques that have been incorporated into all the new A/V components that are HDMI compatible. That's why they are all on board and backing the HDMI standard.


Jon Risch

[Horizons]

Horizons,
I wonder if a custom autoformer would help your situation?
I am working with a custom winding company to get a pair of  2x autoformers out here to test with my XR45.  Mostly for sound quality as I have read another post about a fellow who found his Zero Autoformers set on the 2x setting, improved the sound greatly.
I wonder if it would help with your 1.6's?

Thanks Starch, I have considered this for the Maggies but I would be surprised if it made that much of a difference. Every digital receiver I have tried fails to really move the Maggie 1.6. However, if you come up with a decent volume price, please post and I'll think about it.

I am frankly dissapointed with Wayne's description of the XR70 power supply being less robust than the 45. I guess I was expecting too much. I may now consider picking up 2 used XR45's and biamp/biwire the Maggies. I'm guessing some folks might start selling the XR45 to get the XR70. Also considering using two of the F10 JVC units.

I really like the sound of digital receivers but they don't deliver the current.

[audioengr]

Thanks Starch, I have considered this for the Maggies but I would be surprised if it made that much of a difference. Every digital receiver I have tried fails to really move the Maggie 1.6. However, if you come up with a decent volume price, please post and I'll think about it.

I am frankly dissapointed with Wayne's description of the XR70 power supply being less robust than the 45. I guess I was expecting too much. I may now consider picking up 2 used XR45's and biamp/biwire the Maggies. I'm guessing so ...

I have one too.  This is much prettier than the predecessors.  The unit is actually heavier than the XR45.  The power supply seems about the same to me.  It has a very large tank cap in the middle now, which should make the mounting of a Jensen 4-pole much easier.  The output inductors are identical too, except that they also now have some small air-cores on the board.  My hand-wound ones should still work.  The output and mezzanine boards are very similar but the digital input board has changed.  This should make digital mods easier.  Looks like they improved this a bit when they added the HDMI.  The chassis is a bit taller than the XR45.

I was dissappointed in the bass control of the XR45, even after mods, and I believe that the new amps will probably be no better.  If you are driving Kllipsch's, they will probably work great, but not Magnepans.  I would recommend the Carver Pro for these.  Great bass control.

[Wayne1]

This is the modded SA-XR45 power supply board.




This is the stock SA-XR70 power supply board.

At a quick glance you can see the SA-XR45 has 7 additional electrolytic capacitors and additional circuitry on the right side of the picture. This is what the difference was between the SA-XR25 and the SA-XR45.

The PS used in the SA-XR50 and 70 is more like the one used in the 25 than the 45.

A fair amount of the PS board on the 50 and 70 is taken up with the A & B speaker switching relays.

[Red Dragon Audio]

Horizons,

See that is the thing these amps just can't do; deliver gobs of current.  However, I think the autoformer might just be the solution.

According to Paul Spelt, most amps sound better when running at higher impedance loads(read easier load), because they aren't required push loads of current (which stresses the amplifier).

The other nice thing about raising the impedance; it increases the damping factor of the amp and therefore provides more control.  I know for maggies, a higher damping factor is a must to help control the panels.

Here is a http://www.audiocircle.com/index.php?topic=14535.msg128402#128402&highlight=#128402">post about this very topic that I have been working on.  Read it and the link within it.


Basically, you might be out $15 to ship it to the next guy in line or you might like it and end up spending $165ish.  I'm not charging anyone on the test unit.  I just need to make sure they are reputable and have posted numerous times here.  ChairGuy is in line for it as well as a couple other folks.  If you want to get on the list, just email me and watch for a future post when they arrive.  I'll then get a comprehensive list done then.

[Horizons]

Horizons,

See that is the thing these amps just can't do; deliver gobs of current.  However, I think the autoformer might just be the solution.

According to Paul Spelt, most amps sound better when running at higher impedance loads(read easier load), because they aren't required push loads of current (which stresses the amplifier).

The other nice thing about raising the impedance; it increases the damping factor of the amp and therefore provi ...

Thanks for the info. Put me on the list. Even at the cost for the autoformer + JVC or Panny, this is still half of the cost of the Carver ZR amps. I think this might be worth a try.

[Red Dragon Audio]

Horizons,

I am also calling some other tranny companies now to make sure we're getting the best price.  The tough thing is, most of them want to do huge quanitity deals and are basically not interested in these small quantity batches.

I'm going to keep on it though and I will make an official post once i get a pair in my house.

[Horizons]

Horizons,

I am also calling some other tranny companies now to make sure we're getting the best price.  The tough thing is, most of them want to do huge quanitity deals and are basically not interested in these small quantity batches.

I'm going to keep on it though and I will make an official post once i get a pair in my house.

Thanks for your work on this. I can't understand why a pair of  toroid transformers should cost $450 a pair as Mr. Speltz charges. This seems crazy.

[Red Dragon Audio]

Horizons,

I am also calling some other tranny companies now to make sure we're getting the best price.  The tough thing is, most of them want to do huge quanitity deals and are basically not interested in these small quantity batches.

I'm going to keep on it though and I will make an official post once i get a pair in my house.

Thanks for your work on this. I can't understand why a pair of  toroid transformers should cost $450 a pair as Mr. Speltz charges. This seems crazy.

they are expensive but he is in business doing that.  So he has to charge much more.  Probably double what his costs are just to maintain.

You also have to consider the fact his autoformers are much more complex than the ones I am proposing.  Mine have a primary and secondary winding and that's it.  Your most basic tranny really.

His have various windings and taps that make it hard to design as well as more laborious to wind.

hence the cost difference.  Plus, I am not "selling" these.  I'm just doing the footwork as I want to try to get better sound out of my XR45.  If guys are using the Zero autoformer with $5000 amps then why not try it with a $300 amp?

Anyway, I am hoping to have this ready to go sometime this month but it might get pushed out to the New Year.  I guess good things come to those who wait.  I just don't want to wait...a whole lot longer at least.

[tex-amp]

Thanks Starch, I have considered this for the Maggies but I would be surprised if it made that much of a difference. Every digital receiver I have tried fails to really move the Maggie 1.6. However, if you come up with a decent volume price, please post and I'll think about it.

I am frankly dissapointed with Wayne's description of the XR70 power supply being less robust than the 45. I guess I was expecting too much. I may now consider picking up 2 used XR45's and biamp/biwire the Maggies. I'm guessing so ...

Have you thought about picking up the Flying Moles that are on the trading post?

[Red Dragon Audio]

Thanks Starch, I have considered this for the Maggies but I would be surprised if it made that much of a difference. Every digital receiver I have tried fails to really move the Maggie 1.6. However, if you come up with a decent volume price, please post and I'll think about it.

I am frankly dissapointed with Wayne's description of the XR70 power supply being less robust than the 45. I guess I was expecting too much. I may now consider picking up 2 used XR45's and biamp/biwire the Maggie ...

The Flying Moles are a definite option but they are monoblocks with analog inputs.  Personally I don't want that stage in there because it means I must also have the D/A stage earlier...then an A/D stage there.  I like the straight digital path my XR45 offers.

So $630 for a pair of used Flying Mole monos here on the trading post.  Then you need a preamp, Transport, DAC etc and all the cables.  Your costs go up and up.  With the Panny, you still have to worry about speaker cables, powercord and a quality digital interconnect but that's about it.  Mods are like icing on the cake later on.  I know Wayne and Steve both do a great job of extracting the last bit out of these amps.

The volume control on the XR45 is about perfect .  Zero noise whatsoever.  Black as night background.  The rest of its sound just needs some refining.  Like taking nice 20K gold and refining it to pure and perfect 24k gold.

There is some upper end brightness there sometimes on certain music for me as well as a bit of forwardness to the sound.  I"m hoping the 2x autoformers will help to aleviate that and later on I will perform mods or have Wayne or Steve handle it for me.

I guess one thing everyone has to keep in mind is that these never were and never will be HIGH POWERED AMPS.  They're just not capable of more than they have in there.

Wish I could get hold of the guys in charge at Panasonic and get an "Elite Line" setup.  Maybe I will try.  However it is unlikely they'll even listen.

[tex-amp]

I thought the XR45 didn't give him enough power.  That is why I was wondering about the Flying Moles.