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Hy all!
I recently finished my 18W tmb build from scratch.
It took a long time but with help of coco and a little luck I finished it and got it working from the first time.
This is the first 18W in croatia.
Anyway here are some pics from the building(didnt have much time to take pics.;D)
Enjoy
http://rapidshare.com/files/35240215/New_Folder__2_.rar

Very impressive. The first 18 watt in Croatia!!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Link not working
Great about your amp and what fun having the 1st in your country.
Congrats

Link works fine. Unless you have a premium account you need to click the free download.

Nice amp! How does it sound?

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Simon

yep, that worked
Amp looks great, very nice job

Thank you!
I must thank coco for his big help and assistance over internet in building this amp!

Coco is the best
Wait, where's the clips
If you build you must clip

cybersky built this amp from scratch. I only sent him some parts. His work was fantastic and it was a first build for him as a high school, student project. If you look over the pictures, you'll see what I mean. Very resourceful!

I want to hear the clips too!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I have one question for you guys.
I want to make some measurements with the osciloscop and I want to turn the volume to 10 and because this would be very loud when hooked on the function generator I was figuring that I could use wirewound resistor 8ohms.
Would this me good and are there any chanses to blowing up the OT?
The resistor would have some indutance because the wire and at the same time 8Ohms reistance at all frequncis.

Thank you!

P.S. Sorry for bad English if any!

A 30 watt or more wire wound resistor should do. It wants a ressitive load as i understand it. Inductive loads are more for measuring frequency reponses etc.. (i think)

BBQ sells a nice dummy load and he also sell speaker drivers to use as inductive loads. A 50 watt version would also be ideal for you purpose.

_________________
Simon

Here ya go:
http://www.partsexpress.com/pe/showdetl ... er=019-020

OK.Thanks.
How much is it the bottom frequncy and the top frequncy of the 18W before the gain drops for 3dB?

does anybody know the answer?

I got a problem that developed today.
I turned the amp on and fliped the standbay swich when it starter motor boating loud as hell.
I tried to move some wires with no effect.
What could be wrong?

CyberSky, that's a very interesting question and there has to be a specific answer for a particular amp. There have to be scientific ways it could be measured but certainly beyond anything I have! Only have what's left of my ears

Whilst the actual amp itself can be measured, there are external factors to be considered (also can be measured), input (guitar's response) and output (speaker response) If you check with speaker manufacturers some provide graphs for each model. The only input graphs I have seen have been for mics (in fact EV used to supply an actual trace of the mic you bought, nice touch I thought) Guitar speakers I believe begin to roll off at the upper end around 5.5kHz whereas full range drivers will exceed 20kHz

As for the amp itself there are lots of factors, the OT will have a bearing as frequency in will effect what is put out depending on the OT's response curve and impedance match.

Other factors within the amp are the various filters that are formed and probably most notably are the pre-amp cathode bypass caps (values from 2.2uF - 0.68uF will show marked 'bass' reduction) Couping caps between stages and tonestack caps/resistors can be tailored to effect frequencies.

Power supply too effects how the amp responds as bass notes require more juice and when they don't get it compression occurs, often referred to as sag.

Perception in what we hear is another factor and tight or more defined bass makes an amp appear less bassy.

I know that depends on lot of factors but could do tell me the aproximate number.
I was mesuring it the other day and got some strange numbers the bottom is around 1 khz and the top is at 5khz,could that be possible?

In an amplifier that has worked correctly once, motorboating can be a signal that the decoupling capacitors in the B+ lines of the preamp section are going high impedance and not decoupling properly. Check them and you might have to replace them at least for the preamp. Since the other capacitors are new, you should need to replace ALL of the electrolytic capacitors in the amp (i.e. a cap job)

Pull out V1 andsee if the sound goes away. Repeat with V2 andsee if you can at least narrow down the area where it's happening.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I pulled out the V3 and the boating stopped, I have returned the V2 and the amp is dead silent.
I got the same problem long ago and then I chopsticked some wires and the boatig has gone away.
Could it be that some wire is picking some noise from the heater wires or something like that?

So V2 & 3 in and the amp is silent. V1 in it motorboats? If so, then chopstick again around V1 but it might be a component since it worked before.

Both channels motorboaring ??

The noise it would pick up from heater wiring would be AC hum. Your current problem is more likely interference with one of the signal wires.

Try to make sure that when wires cross over each other, they do so at right angles and there is a separation [i.e. they dont touch] between them as well if possible.

Try to make sure wires dont run parallel and beside each other.

Keep them well away from heater wires. I flatten the heater wires tight to the chassis and 'loop' the signal wires well over them.
If a wire is not going directly to a tube pin, in a very short length, flatten it to the chassis well away from heater wires of course.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

This is the sound clip that shows the noise:
http://www.box.net/shared/92l9a0c5kq

Is this motorboating or something else?

Not motorboating. Try a different tube if you have one. If not the tube [my first suspicion], sounds like a bad coupling cap or tone control cap.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps