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.

[madmax]

So I'm at work looking for some old schematics and I open up one of the cabinets I never use and there it is! A tube amp! 7 months ago I put it together and had a problem with voltage on the outputs. I put it away and totally forgot about it with everything else that was going on at the time. Well, I just ran through the assembly guide and found a wire was missing. Once I install it I hope the thing works properly. Is anyone else so scatterbrained as to forget something like this? I must be loosing it. :)
madmax

[madmax]

She powered up nicely, measures good on a scope, no dangerous external voltages and is showing no signs of any problem! I'll let her run for a few hours then hook up to some cheap speakers. Right now I have 10 ohm resistors as the load. Oh man what a beauty!
madmax

[BlueMDPicker]

I auditioned BlueMDpickers amps, I think he had two of the ones I'm building.

Yep, I had two of them bridged mono driving the Cain & Cain Abbeys for awhile. They're very transparent sounding.

And, yes, you're losing it. ;)

[madmax]

I can't wait to hear it on the horns but given that its a kit I think I will abuse some other speakers first until I feel more comfortable with it. It needs to break in anyway. Well, I got it boxed up and am on my way home. So much for the work I was going to do today, guess I'll be here tomorrow... :D

[madmax]

Let me proudly present: The Transcendent amp kit!

Here is a box of parts needed for high quality sound.

[madmax]

First pic is in almost finished form, still a few wires to attach. The second pic is where I tested it out in on some super low efficient speakers. I was able to power it up and play at full volume all evening without having to worry about the speakers or a lot of noise.

[madmax]

And here it is all together!

[madmax]

Review of the kit:

I wanted one of these amps really badly but they come in kit form and I really don't have a lot of time for this type of activity. Besides that I'm an electrical engineer and see plenty of of this type of work all day every day, not something I like to do as a hobby. With that said I went ahead and ordered it anyway. I put a few full days into building it and found it an easy kit to put together. You need to know almost nothing to do it correctly. The manual is full of all the pics you need as well as drawings and easily worded paragraphs. Pretty much if you can look at pictures you can build this easilly. If you can see and can turn on a soldering iron it is a plus.

I put it all together and measured a few voltages to make sure the unit was safe to touch and safe to connect to a preamp and a pair of speakers. No voltage was on the case, or input lines but there were 30 some volts on the speaker outputs. I sure was glad I decided to check before melting my speakers! I had a wire out of place. It was easy to look through the pics in the manual and find it right away.

After getting it home I first connected to my upstairs rig. It uses a laptop as a source and feeds signal into a Music Hall USB DAC. The speakers are some very inefficient Diahlquist DQ-10's. I played full volume to them all evening just to test the amp and burn it in. The DQ-10s need a lot of power, 200+ watts and this amp only delivers 1 watt or so. They were not loud at all. I listened to it for awhile anyway and was quite surprised that even though I had very little volume I had the sense that the amplifier was taking control over them. The bass had authority and the highs were sparkling. The midrange seemed a little in the background. Anyway, enough of that, lets get to where I hooked them up to the 104DB sensitive horns instead of the 86DB DQ-10's.

I disconnected the Manley 100w tetrode mode mono blocks from my main system and set this little 2 watt monster of sound in their place. I powered it up and dropped the needle in the groove. As I brought the volume up I noticed at about 12:00 on the knob was a pretty good volume for quiet type music. This is the setting where I normally play fairly loud music. Getting a little anxious that maybe this was going to be the loudness limit I put on some harder material and took the volume up to about 3:00. It was quite loud but not stadium loud like the Manleys. It then went to full throttle with no complaints from the amp or speakers. At this point it was too loud so I turned it back down. That was enough of a workout for one day so I shut it down.

This morning I listened to various music and found the amp quite to my liking. Its strong points are a very authoritive quick bass, speedy sounding toe tapping qualities and the ability to play very complex music and allow different textures to dance around the room. The soundstage is exceptionally stable and often times a group of sounds get together and lead to quite an experience. I got goosebumps a few times and marveled at the many sounds I heard. The weak points are power related. With the horns a few watts are as good as a few hundred watts but most ordinary speakers wouldn't be loud enough for many of us. I guess a speaker efficiency of 96DB or greater is most reasonable for this type of amp.

Wow, what an experience this amp provides!
madmax

[BlueMDPicker]

And here it is all together!

You did an excellent job on the amp, Chuck. I'm glad you like it. I liked the pair I had a lot.

[madmax]

After another full evening of listening I'm beyond pointing out the differences between this amplifier and the ones I was using. Its easy to say this is better and that is worse but you have to get over that to really hear whats being presented. After all some aspects are better, some worse.

I'm hearing some really incredible detail, solid bass and smooth highs. The glorious midrange is not something I can claim here. It shows up here and there, actually quite a bit of the time, but is not the biggest player in the overall presentation. When it shows up it is glorious, when it doesn't it doesn't. Maybe this shows that some amps have more color to them than others or maybe it says that midrange glory is not always there, I'm not sure. The way this amp puts all the different textures of complex sounds together is absolutely amazing! These textures and the bass are the true strong points of this amp. If I had it to do over again I would easily buy one of these again. However, my next amp will most likely be a 300B or 45 just so I can try more different things. This one isn't going anywhere soon. ;)
madmax

Edit: Oh yeah, it takes 230 watts from the wall plug to make 2 watts at the output. Amazing little heater here!

[Face]

If you're looking for a SET, you should check this out: http://www.ayonaudio.com/products/amplifier/integrated-amplifier/crossfire.html

I heard one recently and it's a wonderful sounding unit.

[zingo]

Or you could do both and get an OTL 300B. :D

http://www.atma-sphere.com/papers/300b.html

http://www.atma-sphere.com/images/300bfront.jpg

[madmax]

I've been thinking of the bottlehead 300B monoblocks. Then I look at the price and think for more $$ I can get some used Manley 300B mono's and not have to build them.

[zingo]

http://www.audiogon.com/cgi-bin/cls.pl?ampstube&1276716482&/Welborne-Labs-Terraplane-300b-

[madmax]

Thats interesting. Good reviews too. I wish I could try a few different ones and pick the one I like. :)