[OzarkTom]

Rex received the tour amp today and is modding the RCA's and closely checking the batteries. He also said something must be wrong since he also gets about 20-25 hours of use on his.

[rikhav]

If i connect the supplied AC power supply through a true online UPS, will it be same as using the amp on battery power?

[Freo-1]

The short answer is no, not the same as a straight battery setup. 
 
What UPS are you referring to?

[rikhav]

The short answer is no, not the same as a straight battery setup. 
 
What UPS are you referring to?

Was refering to this ups

https://www.emersonnetworkpower.co.in/channels/Common.aspx?id=cPn0S0witHQ=

Issue was that I was only getting industrial grade chargers here in India which are heavy and bulky.

But just yesterday I got to know about a company which makes smps based chargers

[OzarkTom]

Rex charge up the tour battery and found that it  would charge only to 22V, so it has seen better days. We are still waiting on those two 12V Amazon batteries that I mentioned earlier. The total with shipping was $26.

Speaking of my buddy Rex, I went to visit him over the Labor Day holiday and we experimented with the different set-ups. We thought that the 24V  battery sounded about 5-10% better than the 12V. Now if you are using 4 ohm speakers, the 12v might be better. Since one battery was 12v and the other was 24v, we did not hook two amps up. But we did hook up two amps with the AC power supplies, and to my surprise, that sounded the best. The way I understand on that, it has to do with thermal limiting on the amps. The sound was smoother and more open. I want to try that on my system, but do not hold your breath. My power here is very dirty in the town I live in, and battery will probably win.

I am hoping we can get the tour amps back on the road later this week.

[Audioclyde]

I'm not on the tour, but I purchased a modded amp from Tom (with the Cardas RCA's & spkr connections, etc.).  My main amp is the Mastersound Compact 845 SET amp--I feed its 'direct' input from my Monbrison preamp.  Source is the AMR dp-777 DAC, and speakers are Daedalus Audio DA-RMa's, augmented by a REL Strata III sub.

My TBI amp probably only has 100-125 hours on it to date, and I have only  listened to it via AC pwr so far---I'm awaiting the return of my BatteryBuss, at which time it will be connected to the BatteryBuss fed by 24v.  I need to get out and purchase 8 quality AA batteries and try it powered by internal batteries just for comparison sake if nothing else.  Also, most of my listening has been done with the Monbrison pre feeding the TBI; I have the TBI's volume control at max.  To further make some audiophiles shudder, I use the dp-777's analog volume control--so in essence I have 3 (the dp-777, the Shindo and the TBI) volume controls in the signal path.  However, I have found that using the setup to feed the Mastersound amp's direct input (when I only have the volume control of the Shindo and the dp-777 in the signal path) to be outstanding.

Suffice it to say that I am very, very impressed with the modded TBI!  While I won't likely be selling my 845 SET amp anytime soon, the TBI gets really, really close to its sound/magic, and of course at a fraction of the cost.  I've had many solid state amps in the past, including another Class D amp--once I was bitten by the SET bug, however, SS just hasn't been able to satisfy me.  Well, the TBI fills the bill and I have been very contentedly listening to my setup with it installed the past 10 days or so!  It has so much of the SET magic to my ears that I almost find it hard to believe!

Also, note that I have the REL Strata III sub connected via its speaker level inputs to the TBI with no problems whatsoever (some Class D amps share a ground or something so that such hookup cannot be used with them).

Tom, in reading your last post (i.e. the comments about hooking 2 amps up), I'm wondering if somehow 2 TBI's could be used in sort of 'mono' mode, with each powering a single channel, and if there would be any benefit from this (or if the TBI would/could be changed internally to perform in mono mode)?  These little guys are so good that considering the price, I'd definitely want to add another if they can be used in this manner.....

Randy

[rockadanny]

I'm awaiting the return of my BatteryBuss, at which time it will be connected to the BatteryBuss fed by 24v.  I need to get out and purchase 8 quality AA batteries and try it powered by internal batteries just for comparison sake if nothing else.

Randy - looking forward to your impression when you do this. Please post. Thank you.

[rikhav]

My TBI amp probably only has 100-125 hours on it to date, and I have only  listened to it via AC pwr so far

If this is the case then be ready for a big surprise when you listen to the amp with battery power. For me there was a day and night difference between and battery and AC power

[gilesw]

@wushuliu I was interested to see your post about the treble being too bright. I've got the same problem with this amp. I've run some tests with a sound meter app on my phone and 6.5khz is loudest. I'm going to try out some resistors inside my floorstanders on the tweeter feed.

[wushuliu]

I didn't find the treble bright per se, it was a very slight emphasis and disappeared after replacing binding posts and rca's/wiring...

[Freo-1]

I didn't find the treble bright per se, it was a very slight emphasis and disappeared after replacing binding posts and rca's/wiring...

I agree 100% with your assessment.

[gilesw]

I've just taken mine apart tonight actually. Did you replace the internal cable as well as the binding post themselves? and did you remove the white plug socket and solder the cable directly onto the board?

I've been looking at those cardas binding posts and it looks like I get get them here for £50 for the two:-

http://www.hificollective.co.uk/components/binding_posts.html

Not obvious if they come as pairs actually.

On the rca front you presumably ran cable.

[wushuliu]

I've just taken mine apart tonight actually. Did you replace the internal cable as well as the binding post themselves? and did you remove the white plug socket and solder the cable directly onto the board?

Yes

[gilesw]

@Audioclyde I'm running on 8 odd AA batteries I had kicking about. I didn't really think much of the amp until I used it with those.

[Audioclyde]

gilesw, I tried it on some Ultimate Lithium AA's last night for awhile, but much preferred it on AC pwr--I got a bit of glare, overemphasis of the treble on AA battery pwr.  I'm still eager to feed if from 24v batteries via my BatteryBuss.

Randy

[gilesw]

Interesting. I do have issues with the treble being too harsh but I've had it down to my various new components just being too revealing and showing up my speakers. The main difference I noticed going to battery was the amp sounded more natural. I'm mulling over whether I should build a 24v battery pack at the moment. Doesn't sound great if you need to replace it all the time though.

[DaveC113]

I'd bet something like this PS would be as good as any battery...

http://www.ebay.com/itm/NEW-LAMBDA-24VDC-LINEAR-REGULATED-POWER-SUPPLY-WITH-MANUAL-LRS-54-24-/200753570672?pt=LH_DefaultDomain_0&hash=item2ebdd86370

[srb]

I'd bet something like this PS would be as good as any battery...

A good industrial power supply, but how good is it for audio applications?  It has a tightly regulated voltage output, but a fairly high 100mV peak to peak ripple for a linear audio power supply.
 
Steve

[wushuliu]

I'd bet something like this PS would be as good as any battery...

http://www.ebay.com/itm/NEW-LAMBDA-24VDC-LINEAR-REGULATED-POWER-SUPPLY-WITH-MANUAL-LRS-54-24-/200753570672?pt=LH_DefaultDomain_0&hash=item2ebdd86370

I also found the Meanwell 24v SP150 SMPS to be on par with 24v (x16 D) alkaline batteries. Only $50 from Jameco. However both it and the Lambda involve wiring to mains voltage and some folks may feel more comfortable sticking with batteries.

Would be great if other folks did some comparisons though.

[rikhav]

I have to make a wiring harness to connect the battery to the amp.

Any suggestions on what cable should i use since the pin which goes into the amp accepts very thin gauge cables