The Amp Garage

joe6v6 wrote:Can someone point me to the schematic for the high cut control, I cant seem to locate it.

[img783]http://pages.videotron.com/chigbl/cutcontrol.jpg[/img]

I need to try these. What values have you used for the hi cut control? I have a schematic showing a 250K pot and a .0047uf. That's exactly what I used.... Let me know how it turns out. I finally found the time to install the hi cut and that's a keeper for me. As you mentionned, I also think the low...

tsl602000 wrote:The most important mods are the hi cut control and the 22k tail resistor. They really changed my amp.

I need to try these. What values have you used for the hi cut control? I have a schematic showing a 250K pot and a .0047uf.

Welcome Matt,

I am sure you will enjoy it here!

What is (are) your preferred amp(s) in the dozen you built?

Gilles

Thanks Elcabong! Did you have a aluminium or steel chassis built? That's a good idea of getting only the opt shipped in! Stew It is made of 0.080" aluminium. It is easier to work. I did not use the original Express chassis size as you can see in its birth day thread http://ampgarage.com/forum/viewt...

Hi stoo,

I had the chassis made in a local shop for $35 CDN. You could use an Hammond chassis but they are a little too thin to my taste.

I used an Hammond 272JX for the PT but got the OT from Moose http://www.toneslut.com

A quick test could be to measure the voltage drop across the 1k resistor and calculate the current draw at that point. If it appears too high, you can then measure across the 18k2, 9k1 and so on and maybe isolate the problematic section.

Sure you can. I did that for a while and found that the cleans I could get were nicer to my ear, more Fendery. But the bass response was not to my taste at distortion level.

I went back to EL34 and do prefer them in there!

I have experienced that to some extent with another amp I built before. I spent some time with a chopstick moving and rearranging wires and it fixed my problem. So basically I tried to keep high voltages wires down close to the chassis, signal wires higher. And have wires that intersect at 90 degree...

Steve, I also experimented with different impedances on my TW clone. I finally decided to use the 5.2k tap; just my preference. Here is an interesting article I found on load impedance even if it is for Class A amplifier. http://www.obsoleteelectronics.com/Transformers/Load_Impedance/load_impedance....

You have it right. Especially the OT. #1 is the primary impedance. All of Ken Fischer's designs that I've seen use relatively high Zpri impedances, relative to Fender/Marshall/Hiwatt, for instance. Other things being equal, this generally reduces output but also does nice harmonic stuff to the tone...

That's an interesting layout. Nice clean build too! I have done something in that direction with my amp but I kept the filter caps grouped: http://ampgarage.com/forum/viewtopic.php?t=658&highlight= I had first planned to distribute the filtering but my board became too long. Using smaller caps and a...

drz400 wrote:As a constant signal (not peaks) 50mv or around -25db is standard I see

I am not sure to follow you here. Do you mean 50mV RMS, which would translate to around 125 p-p?

I usually go with 200mV p-p 1kHz signal.

I do not know the wiring for this specific OT but it is nothing to worry about. If the amp howls when you first start it, you reverse the leads.

The North American standard is to have the switches on when they are in the up position. I know that early Marshall had it the way around.

This clip motivated me to build an Express:

http://ampgarage.com/forum/files/trainw ... s_paul.mp3

I love the way it progress from clean to full bore! It's orgasmic!