Transcendent amp kit

[madmax]

I got it in the mail last night and I'm about ready to start! I hope I don't blow myself up... :eek:

http://www.transcendentsound.com/singleended.htm

madmax

[treitz3]

1.5 watts? :eek:

Say it ain't so bro'! :D

[Face]

Very cool, keep us updated.

[GV#27]

Cool,do you have some big K horns to use with it?:D

Single ended and OTL I assume there are some BIG coupling caps at the output.

[madmax]

I just finished most of the hardware steps, its about time to start soldering. I picked up some 4% WBT solder, man that stuff got expensive. $81 a roll! I probably should have just used the standard solder I have but who knows, maybe it will make a difference.

Its 1.5 wpc or 4 wpc bridged. I may have to buy a second one. I'll be using it with my Avantgarde Duo's which are 104 db efficient. I tried the Duo's with the little 6w t-amp and it kicked butt, extremely loud. 1.5w may do it. :)

madmax

[dorokusai]

Hey, if you're gonna build something nice like that Chuck...buy the good stuff.

[danz1906]

Good looking Amp!

[zingo]

I've heard they make some good stuff and have always been interested in their products. Keep posting the updates and good luck with the build!

http://www.transcendentsound.com/TranscendentSEOTLfront02web.jpg

[megasat16]

I got it in the mail last night and I'm about ready to start! I hope I don't blow myself up... :eek:

http://www.transcendentsound.com/singleended.htm

madmax

I am calling Homeland Security. You know I still got your address? :D

Very Cool Project! Keep us posted!

[dorokusai]

Hey Chuck, you know BlueMDpicker has built a few of those pieces...maybe drop him a line.

[madmax]

I auditioned BlueMDpickers amps, I think he had two of the ones I'm building. His didn't go as loud as I would have liked but I think his speakers were about 96 db efficient. He did say something about them getting louder after putting a preamp in front of them.

OK, time to start todays fun with the project!
madmax

[mhardy6647]

I am very curious to hear what you think about that little amp. It's an ingenious and (relatively) inexpensive way to sample OTL; certainly has a lot of potential if one has sufficiently senstive speakers (no dearth of those around here!).

Best of luck; keep us posted!

[madmax]

Just finished the power supply and the output board. Its starting to look like an amp. Now, its time for lunch!
madmax

[madmax]

Just got back from lunch :D and ready to start day 3 on this project. I have 10 hours in it so far, hopefully I can finish it up today.
madmax

[Ricardo]

Pictures.... or you bought it assembled.

[Polkersince85]

There's a nice pair of Altec 16 ohm horns on the Bay.

[madmax]

Pictures.... or you bought it assembled.

Ha ha, I knew there would be skeptics... Got the camera in hand. :D

I'll check out those horns.
madmax

[Polkersince85]

There's a nice pair of Altec 16 ohm horns on the Bay.

http://cgi.ebay.com/Altec-288-16G-horn-drivers-Outstanding-Pair-ALNICO_W0QQitemZ180414811830QQcmdZViewItemQQptZVin tage_Electronics_R2?hash=item2a018f8eb6&_trksid=p3911.c0.m14

[madmax]

I saw another horn/driver combo and decided to give it a try. Its the ones for $450.

"Matching Altec 806A Drivers & H-811B Horns Valencia 846


Up for grabs is a Pair of Matching Altec Lansing 806A Drivers with H-811B Horns. These drivers and horns are in excellent condition, work flawlessly and sound incredible!! They came out of a pair of Altec Valencia 846A Cabinets and are guaranteed to work or your money back. The diaphragms are original and are in excellent condition as well.

FEATURES:

16 Ohms
Horn Dimensions: 18 3/4”W x 14” D x 8 5/8” H
Distribution Pattern: 90° H x 40° V
Cast Aluminum Horns
Driver Numbers: 391917 & 391917"

[madmax]

Darn, still not done. Still have the switch, LED and a little AC wiring to do. I guess I'll hit that tomorrow rather than take a chance on messing something up tonight. So far this kit has been a breeze but there are a lot of steps to do.
madmax

[madmax]

OK, I spent another 4 hours today and finished it up. I powered up and read 34V AC on each of the speaker outputs, no load was attached. I emailed them to find out if this is a problem. It could be normal with no load but I'm not sure. Cross your fingers.
At least it didn't blow up or something. :)
madmax

[GV#27]

There shouldn't be anything (other than a few mv of noise) on the output with no signal applied.

[megasat16]

I powered up and read 34V AC on each of the speaker outputs, no load was attached.

How could this happen? Did you double check everything. I really think you should get a dummy load from parts express for testing DIY amps. Your speakers and your wallet will thank you! ;)

[mhardy6647]

OK, I spent another 4 hours today and finished it up. I powered up and read 34V AC on each of the speaker outputs, no load was attached. I emailed them to find out if this is a problem. It could be normal with no load but I'm not sure. Cross your fingers.
At least it didn't blow up or something. :)
madmax

aiyeee! It's probably HUM (and plenty of it); sounds like the AC P/S is going straight through to the outputs. That would cook your speakers; 34 RMS V AC (if that's an RMS reading) would be 144 watts continuous into 8 ohms.
Even if your ACV reading is peak to peak; 34V peak to peak is 12 V RMS which would be 18 watts continuous into 8 ohms. Still bad for speakers.

fun formulas for electronics:

E = I*R (Ohm's Law)
P = I^2*R = E*I

E = voltage (V)
I = current (A)
R = resistance (Ohms)
P = power (W)

V(rms) = V(peak to peak)/(2*SQRT(2))

You don't somehow have AC going to ground, do you?

Yes, you should have a dummy load; PartsExpress sells nice ones, or you can just get a pair of noninductive power resistors (5 or 10W for an amp like that is OK) of roughly 8 ohms (5 or 10 is close enough!) for testing.

I don't s'pose you have a scope or a frequency counter to look at that AC signal, do you? I am guessing its 60 Hz, but mebbie not...

Well, I guess, on the bright side, you dont' have DC on the outputs?!

EDIT: Is that 34 VAC with respect to ground? Where do you have the other probe connected (the "-" speaker connection, or the chassis)?

[zingo]

Agree on the load. I just use about 5w of resistors soldered together and heat-shrinked in an 8ohm load and it provides plenty of help when testing amps.

[thsmith]

How is it coming madmax ?

Would this amp drive a pair of SDA-1Cs ?

I am looking at a couple of kits that are rated between 40-60wpc.

[mhardy6647]

Agree on the load. I just use about 5w of resistors soldered together and heat-shrinked in an 8ohm load and it provides plenty of help when testing amps.

Y'know... it dawned on me that,for all I know, an unloaded OTL amp may do weird and wonderful things (such as powerful HF oscillation?). I just don't know...
I.e., testing with the outputs loaded may sho'nuff be preferred for OTLs just as it is for transformer-coupled amps.

How is it coming madmax ?

Would this amp drive a pair of SDA-1Cs ?

I am looking at a couple of kits that are rated between 40-60wpc.


umm... the titular amp in the case of this thread is 1.5 watts per channel.
There are 40-60 wpc OTL amps, but they're a bit pricey (and you can heat your listening room with 'em).



These little guys, for instance:
http://www.atma-sphere.com/products/index.html

http://www.atma-sphere.com/images/m60.jpg

[Face]

Those are ugly as sin.

[mhardy6647]

Those are ugly as sin.

hmm -- I'd describe them as purposeful looking. They remind me of locomotives, somehow.

Actually, what they really remind me of is an ancient piece of laboratory instrumentation called a Klett colorimeter. I suspect I am the only person here who knows what a Klett is, and I'd probably bet money that I am the only one who's actually used a Klett...

http://www.diversified-equipment.com/Pics/4630.jpg

heck, looks like they still make 'em...

[analog97]

Ain't that thing a device to measure turbidity? Pretty sure I used something like that in an old microbiology class.

[mhardy6647]

Ain't that thing a device to measure turbidity? Pretty sure I used something like that in an old microbiology class.

yup, exactly...

[disneyjoe7]

This 34vac could it be because it's single ended amp. A cap to the output giving you voltage if it's not loaded, behaps you could add a load of some kind to test. Now nothing you wish too use in the future, just a test speaker or resistor 8ohm 5w.

[madmax]

Bruce from transcendent answered my question about the voltage, it shouldn't be there. He said he can only think a wiring mistake was made. Thats easy, I can just follow through the manual again to check the wiring. There are a lot of connections for sure and one geezing moment could cause a mistake. I'm just happy I had the foresight to test a few things before hooking up to other equipment. The manual assumes everything is done correctly and just tells you to hook it up. I was afraid to try a load because if something is miswired a load could pull a lot of current and possibly stress or fry some of the components.

madmax

[strider]

Have you had any luck, 'max?

[madmax]

Have you had any luck, 'max?

I haven't had time to get back to it. I'm having a new roof put on the house plus having it painted at the same time. Lots of things going on this week.