Another 50W Non-HRM reverb

[markusw]

This one is built using a brown note deluxe 44 kit as a platform.
Basically, it follows the "grail" schematics with a couple of modifications. Cleans are 100k/1k5/10u. Tone stack is switchable (push pull Master pot with switch) between 80s and skyliner. Reverb is a dual concentric pot with separate knobs for clean and OD. Reverb itself is Gary's single tube reverb.
Gil's OD entrance mod at the moment with about 14n.
Tubes at the moment are Philips 12ax7 for V1and V2, EH for the reverb, JJ ECC803S for PI, and Winged C 6L6.
Initially, I wanted to do DC heaters for the preamp tubes but I was too stupid to use a bridge rectifier. Since it obviously didn't work with just two diodes I changed to AC heaters. The huge black chassis mount cap is derived from this mistake.
I was sure that AC heaters would be noisier than my previous build that has DC heaters. I was wrong. Absolutely no difference even with volume and master at 100%.

Although the quality of the pics and the guts are actually disgusting compared to UltraHookedOnPhonix's recent 100W Bluesmaster build here are some pics.
Hope you don't throw up

Since the recording setup is installed in the rehearsal room I'm positive that some clips will follow.


Peace,

Markus

[Structo]

Nice!

I wonder if the D'lite chassis are smaller than the ODS chassis?

Is this your first D style amp?

You mention the 100K on the clean channel, do you have the 220K/150K on the OD?

What is the 4th relay board with the trimmer on it?


I was wondering about using the lower plates on the clean channel and if that improves it any.
Currently I have the 220K/150K on both.

[markusw]

Yup, the Dlite chassis is a couple of inches less wide.
I prefer the "normal" width. It's much easier to work with IMHO.
On the other hand for my back it is nice to have the amp a little more compact.
This is my second D style build. It basically is exactly like my first build except the stone stack switching and the dual reverb pot.

The OD is 220k/150. With my first build I did some tests comparing 100k cleans to 220k/150. I clealy preferred the 100k cleans.

The 4th relay board switches between 80s and skyliner. With the trim pot the bottom end of the PAB can be adjusted. Works nicely. The Vactrol enables the fat PAB only with skyliner stack.

Peace,

Markus

[Guitarman18]

markusw,

Your amp looks great.



With your 'fat PAB' setup, did you go with the resistor method and use the trimmer for that? What trimmer values worked for you?

Cheers,

Paul.[/quote]

[markusw]

With your 'fat PAB' setup, did you go with the resistor method and use the trimmer for that? What trimmer values worked for you?

Cheers,

Paul.

I used a 5M trimmer. A 2M5 trimmer should work too. Advantage of the 5M trimmer is that you can start with "normal PAB" if you set it to 5M. With a 2M5 you probably will have a little more bottom end compared to "normal PAB" even if you set it to 100%.

Regards,

Markus

[lovetone]

Nice Build Man,

Can i ask why you marked the capacitors with a black line on one end?

[Cliff Schecht]

The non-polarized caps actually do have a preference as to which way they go in a circuit. The striped line is always meant to go towards the lower impedance side of the circuit. Supposedly it cuts down on noise (yes, caps have noise too!) but I personally haven't tested or verified this, although I'm sure others have.

[dobbhill]

Here's some good info about caps:
http://www.aikenamps.com/
Go to Tech Info, then Advanced.
The article is the last on the list.
Hope this helps.

D

[lovetone]

Thanks i'll have a look at the link, if they are not marked how would you test them?

[dobbhill]

.....included in the article......

how would you test them?

[markusw]

Nice Build Man,

Can i ask why you marked the capacitors with a black line on one end?

Seems I'm too late for answering
To be honest I also never checked whether it makes any difference but considering the number of amps I build (maximum one per year) I just do it

Thanks i'll have a look at the link, if they are not marked how would you test them?

I just connect the cap with alligator wires to my USB audio interface with the gain cranked up. While holding the cap I check the 50 Hz signal level. If the cap is connected the "wrong" way the signal is roughly twice as strong.
Edit: Forgot to mention. I use Visual Analyzer software as a scope.