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Skywave-Rider
02-21-2008, 04:40 PM
After reading posts from T-Amp users, I wonder, is there any consensus on these now that the dust has settled?

I'm about to bi-amp a system (not my Altec 9844s,) and wonder if you think any of the T-Amps, Super-T or Gen II T, would drive the top very well. In that system, the driver will be a BMS 4552ND. It's not going to be used in a high amplitude application, but it does have to be clean and accurate. The bottom will be powered by a Crown PS200.


I have other amp options, including a second PS200, but that's tied up with my Altecs in another location. Should I bite the bullet and carry that thing back and forth?:(

Can cheap be good?

Steve71
02-21-2008, 05:47 PM
After reading posts from T-Amp users, I wonder, is there any consensus on these now that the dust has settled?

I'm about to bi-amp a system (not my Altec 9844s,) and wonder if you think any of the T-Amps, Super-T or Gen II T, would drive the top very well. In that system, the driver will be a BMS 4552ND. It's not going to be used in a high amplitude application, but it does have to be clean and accurate. The bottom will be powered by a Crown PS200.


I have other amp options, including a second PS200, but that's tied up with my Altecs in another location. Should I bite the bullet and carry that thing back and forth?:(

Can cheap be good?

I'm using a Trend's Audio TA-10.1 (same chip as the t-amp) to power Altec 288 K compression drivers on MR-64 horns from 500hz on up. Prior to that I was using a crown XLS 402D. The top end is a little soft on the Altec's, but what is there is good with the T-amp. It's got a little more detail and less distortion than the crown.

clmrt
02-21-2008, 06:29 PM
It's worth the $50 to find out for yourself. I wound up giving mine to an audio-starved buddy.

Never tried bi-amping with it. Used it with Altec 3000H / 414's in the Seville and it was really good kit for low-level playback.

Woofer
02-21-2008, 06:51 PM
I Bi-amp using a pair of T-Amps that I built, for my 'baby' stereo, and to be quite honest, it's what I use nearly ALL of the time now. (volume is not my first priority, so they do the business quite nicely as far as quality is concerned, plus, they do go quite loud, given the chance, and efficient speakers.)
I've got a pair of 4301's which I use one of the T-amps on, and an an old pair of L40's as Subs which I use the other one on, and a very old DBX Boom Box which has the bonus of being a X-over too at around 250Hz.
I must say, at low volumes, it compares very favourably against some very pricey alternatives, and gives my 'BIG' stereo (Quad-amped Phase Linear/JBL bins, mids and horns and slots etc etc) a run for the money. ;)

Skywave-Rider
02-21-2008, 07:06 PM
I'm using a Trend's Audio TA-10.1 (same chip as the t-amp) to power Altec 288 K compression drivers on MR-64 horns from 500hz on up. Prior to that I was using a crown XLS 402D. The top end is a little soft on the Altec's, but what is there is good with the T-amp. It's got a little more detail and less distortion than the crown.

Is that comparo to the Gen II T (the $50.00 unit) or the 3x the price Super T?

I'm pretty impressed by your responses.
I could gamble $50 to hear what happens. I have a good regulated 12v supply already.

Steve71
02-21-2008, 07:52 PM
Is that comparo to the Gen II T (the $50.00 unit) or the 3x the price Super T?

I'm pretty impressed by your responses.
I could gamble $50 to hear what happens. I have a good regulated 12v supply already.

It's billed as an audiophile version of the SI and cost about $150. 6moons did a nice review on it.

http://www.6moons.com/audioreviews/trends/ta10.html

I found a used one for sale locally for not much more than an sonic impact + power supply, so for me it was a no brainier.... If you've already got a PS, $150 is a bit steep compared to a gen I sonic impact.

As far as volume is concerned it shouldn't be a problem for home use with that BMS driver which is 115db/w/m (same as my Altec)... the T-amps are really only 5 watts into 8ohms.

Skywave-Rider
02-21-2008, 09:51 PM
It's billed as an audiophile version of the SI and cost about $150. 6moons did a nice review on it.

http://www.6moons.com/audioreviews/trends/ta10.html


Thanks for the tip, just read it. Looks pretty great!

scorpio
02-22-2008, 12:23 AM
I'm running a 3-ways with active filtering between bass and mid-high. The mid-high combo (JBL 2450 + 2405, simple 1st order filter in between) I have been using with a Trends TA-10 for about a year now, this replaced a 10* more expensive 2A3 SET. Musically (and practically) speaking, it sounds just as good to me. Only drawbacks are a higher noise floor, which can be annoying at night on very soft pieces, and the power-on transient which goes straight to the drivers, I can't manage to fully get rid of it, even playing with the bias. Advantage is that it does not need 20 mins to fully warm up and come on balance, good when you just have time for a very short listening session!

I plan to get back to the SET one of these days, after this long break, it will be the ultimate test! I tried the TA-10 because my SET has a nasty ground loop that I can only eliminate by inserting a decoupling transfo in one of the cables from the preamp, if I use a transfo in each cable, the situation gets worse, even if it's theoretical, I don't like using different cable types for each channel.

For me, it was a very well spend 100 euros, if I don't use it in this system anymore, it will find a use in a secondary one, or to power my Audio-technica earspekers.

pos
02-22-2008, 02:25 AM
I have tried the original Sonic Impact T-amp in a 3 way active setup, on a 2416H and le85, and have faced several problems:
- some hiss can be heard with such sensible drivers
- the amp emit a noise when turn on or off (not a real DC thump because of the caps on the output, but still anoying when used on some expensive 2435h...)
- the volume control is crapy, and the L/R balance is wrong. This is really a problem in an active setup because if the balance vary with each amp you totaly loose coherency and blend between drivers.

I am sure all of the above can be resolved:
- the hiss might be due to some cheap components in the original t-amp
- the super T-amp comes with a timed relay that prevent on/off noise, and such a mechanism can be added to any amp (albeit not that cheap when compared to the price of the amp)
- the balance can be adjusted with some other device

hjames
02-22-2008, 03:51 AM
It sounded very interesting - so after reading the full review, I clicked the manufacturers site link - http://www.trendsaudio.com/ (http://www.trendsaudio.com/)

Maybe its just the east coast ice storm, but I get "site not found"


It's billed as an audiophile version of the SI and cost about $150. 6moons did a nice review on it.

http://www.6moons.com/audioreviews/trends/ta10.html

I found a used one for sale locally for not much more than an sonic impact + power supply, so for me it was a no brainier.... If you've already got a PS, $150 is a bit steep compared to a gen I sonic impact.

As far as volume is concerned it shouldn't be a problem for home use with that BMS driver which is 115db/w/m (same as my Altec)... the T-amps are really only 5 watts into 8ohms.

Steve71
02-22-2008, 06:33 AM
Yeah, it looks like the site is down...

Just to echo what some others have said, I do get a bit of hiss with the TA- 10.1, but I can only hear it if the room is pretty much silent. There is a bit of power on noise, but not enough to concern me.

The one thing I really liked about the TA 10.1 was the ability to bi-pass the (very average) volume pot and use it as a power amp. You just need to change some internal jumpers.

At any rate there are plenty of TA2024 based amps out there. There's even some ready made kits for $20 on epay.

http://cgi.ebay.com/2-15-watt-4ohm-TA2024-D-class-Audio-Amplifier-Board_W0QQitemZ230224629555QQihZ013QQcategoryZ3978 3QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Check out DIYaudio.com forums for more info. There was a thread discussing these kits.

Skywave-Rider
02-22-2008, 06:53 AM
It sounded very interesting - so after reading the full review, I clicked the manufacturers site link - http://www.trendsaudio.com/ (http://www.trendsaudio.com/)

Maybe its just the east coast ice storm, but I get "site not found"

It's back up hjames, try it again. They're apparently made in Hong Kong.


...several problems:
- some hiss can be heard with such sensible drivers
- the amp emit a noise when turn on or off (not a real DC thump because of the caps on the output, but still anoying when used on some expensive 2435h...)
- the volume control is crapy, and the L/R balance is wrong. This is really a problem in an active setup because if the balance vary with each amp you totaly loose coherency and blend between drivers.

I am sure all of the above can be resolved:
- the hiss might be due to some cheap components in the original t-amp
- the super T-amp comes with a timed relay that prevent on/off noise, and such a mechanism can be added to any amp (albeit not that cheap when compared to the price of the amp)
- the balance can be adjusted with some other device

This is probably a good reason to go with a Super T, for the relay. OTOH, In that 6Moons article, they state the Trends amp is not driven as hard as the T-Amps, resulting in lower distortion.


I plan to get back to the SET one of these days, after this long break, it will be the ultimate test! I tried the TA-10 because my SET has a nasty ground loop that I can only eliminate by inserting a decoupling transfo in one of the cables from the preamp, if I use a transfo in each cable, the situation gets worse, even if it's theoretical, I don't like using different cable types for each channel.

Let us know what your immediate impression is when you finally go back to the SET amp. Should be interesting. I had a ground loop problem only when using my tube amp and only with one piece of equipment. But this went away when I inserted a Variac in front of the tube amp. It takes down my VAC to 110 for the tube amp only, but also acts to isolate that amp from any ground loop return. I would suggest an AC power isolation transformer in your case. I need the Variac because my amp is c. 1961.

Thanks for all of your impressions, I think they are helpful. I think that the hiss is the biggest downside for me. I do work at low to moderate volumes. As far as the transient at power up/down, I think I would leave the thing on 24/7. Although I tend to think the snap is not strong enough to hurt the driver; tell me if I'm wrong.

Nobody's really complaining about the quality of the sound, at least that above noise level. Hmmmm.

Anybody think the cheap 50.00 T-Amp is in the running for my application, or should I onlty consider the Super-T or the Trends Audio?:)

Skywave-Rider
02-22-2008, 07:02 AM
At any rate there are plenty of TA2024 based amps out there. There's even some ready made kits for $20 on epay.

http://cgi.ebay.com/2-15-watt-4ohm-TA2024-D-class-Audio-Amplifier-Board_W0QQitemZ230224629555QQihZ013QQcategoryZ3978 3QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Check out DIYaudio.com forums for more info. There was a thread discussing these kits.

If that could be bridged to mono, I'd buy 2 of those kits, and mount them at the rear of the driver. Thanks Steve, I'll look for some DIY info on that.

Steve71
02-22-2008, 07:52 AM
If that could be bridged to mono, I'd buy 2 of those kits, and mount them at the rear of the driver. Thanks Steve, I'll look for some DIY info on that.

You're welcome :). Unfortunately I'm pretty certain you can't bridge T-amps. But five clean watts should give you 118db at a 10 foot listening position

SPL calculator:
http://myhometheater.homestead.com/splcalculator.html

scorpio
02-25-2008, 12:44 AM
It sounded very interesting - so after reading the full review, I clicked the manufacturers site link - http://www.trendsaudio.com/ (http://www.trendsaudio.com/)

Maybe its just the east coast ice storm, but I get "site not found"
If any problem, you should be able to order it from buyoyo.com directly from HK, they were unbeliveably efficient when I ordered it (faster to be delivered from HK that to have a parcel delivered by the post within Belgium!).

Skywave-Rider
02-25-2008, 01:31 AM
To follow up, I ordered the Trends Audio unit.
Thanks for all your input!
I'll let u know how it goes.:)

scorpio
02-26-2008, 12:57 PM
Let us know what your immediate impression is when you finally go back to the SET amp.

Well, this wasn't on my immediate plan, but it tickled my curiosity, so I did a quick & dirty swap tonight (meaning not the best connectors and setting the filter by ear). Result is that the SET has a more spacious presentation, and is clearly more refined in the highs than the Trends, it is also quieter when the ground loop is tamed.

It is however not shocking difference, I would live happily with both, but going back to the SET, I have to conclude that sonically, it is the superior of the two. Drawback is that it takes a lot more real estate and $.

I'll do a little fine tuning and listening for a couple of days, and at the week-end try to do some A/B swaps since I'll have the X-over dialed in for both by then, I'll let you know if I changed my mind,

Skywave-Rider
02-26-2008, 08:51 PM
Well Scorpio, it's good to know that beautiful technology can still prevail. Although the chip amp must be pretty decent to compete at that level. Let us know what happens when you tweak your setup.
:)
I have not received delivery of the little Trends amp yet.

Skywave-Rider
02-28-2008, 06:24 PM
Got my Behringer CX3400 running today. Still don't have the Trends amp, so using my Magnavox 6v6 tube amp on top. Sounds good, fun to play with. Easy to set up, especially with RTA. :D

By the time I get the chip amp, I'll hopefully have my BMS drivers. (Using a dome tweeter for the moment on this setup.)

Zilch
03-05-2008, 12:18 AM
Shhhhh.... :scold:

Folks'll think this is easy with the right tools.... ;)

Skywave-Rider
03-07-2008, 06:59 AM
I have my Trends Audio chip amp. BMS drivers are still in transit, so I can't check it with the eventual biamp system.

Using the Trends amp on my Heresys is fun. Pleasant top end, not much low end power as expected.

And I note that I have heard this sound before. Must be the same amp chip used in Tivoli radios. A little grainy. At the same time, clean when not overdriven. Not tube like, as the manufacturers hype.

Should be good amping the top end though.

Barely gets warm on my efficient Klipsch.

I don't play anything too loudly in my apt. though.

Steve71
03-07-2008, 07:15 AM
And I note that I have heard this sound before. Must be the same amp chip used in Tivoli radios. A little grainy.

FWIW I've never believed much in amp break-in, but I've read more than a few times that the chip sound grainy out of the box. I bought mine used and I don't notice any grain at all unless it's on the recording.

Did you try your other power supply? I noticed a big difference in sound stage size and open-ness when I went to a better power supply.

Skywave-Rider
03-07-2008, 09:26 AM
Did you try your other power supply? I noticed a big difference in sound stage size and open-ness when I went to a better power supply.

Not yet Steve. I will but I have to dig around for the right connector and then make up a cable.

It's a good product and reasonably priced.
I get the turn on transients but they are of no consequence.

OH! Forgot to mention. Standard dual banana plugs are slightly too wide for the binding posts on the amp. :blink:
You'd have to use single banana plugs to make that work, or bare wire, as I am doing.

Skywave-Rider
03-19-2008, 09:57 AM
The T-Amp biamp setup is working great, though I am waiting for parts to finalize my passive compensation circuit for the BMS 4550s. Right now I'm EQing to flatten the top end. Here are some pics, the Trends amp is on the T-Table.


The Crown PS200 for low end, Behringer DCX3300 active analog crossover, DEQ2496 for EQ/RTA, the Technics amp is for my Heresys. The speakers are EV Sentrys with a JBL horn on top and BMS drivers. Dome tweeter is disabled. X-over is 1.2kHz.

Krunchy
03-19-2008, 11:34 AM
Hey Skywave! Like the set-up you got there, that JVC CD player looks very familiar, is that the XL-V-141? That was my first player, I still have mine from 91-93, works great and I love a lot of the simple features that it came with. Sounds like you'r having some fun :)

Skywave-Rider
03-19-2008, 08:30 PM
Thanks, Krunchy. Seems like I'm always waiting for Parts Express shipments....

Well you have a good eye. But the JVC is a XLV241. I've had it forever too. Good converter on that. Keeps on playin'. Thought I'd have some new format player by now, but it never happened.

Want to hear those JBLs, when's the listening party....?;)

Krunchy
03-20-2008, 04:42 AM
Hi Skywave, Packages from parts express are always good, Seawolf turned me onto them, wish more companies were like them, quick and efficient.
The listening Party (emphasis on the latter here) will probably take place when it gets a little warmer out, probably may or june, should be fun getting to meet other LH members in person. I'll keep postd. dig the new ayvatar :).