What 1x12 combo... Thinking of going for a DSL401C.

rico

CHrisP86 said:

Picking up a DSL401 tomorrow.

Have a Neo Creamback I can put in it, so that’s the speaker upgrade done.

Will try jumping the fx loop as well.

Will make sure it’s a keeper before doing the heat sink but will keep a fan close by! 

Any other tips for eq’ing or getting a ‘good’ sound out of it? 

Do you use pedals for drive? I far prefer using the clean channel with pedals and I have it set thusly:

- gain at 9 oclock
- bass at 3 oclock
- mid at 2 oclock
- treble at 12 oclock
- Fx loop jumpered and mix on full
- master about 4 oclock 

It’s fairly loud like that with an OCD in front! 

ICBM

Voxman said:

I know, I know...its tehnically class A/B...but it was described as class A by Laney just as the Vox AC30 was originally described as Class A by Vox.

I don’t think Vox did describe the AC30 as ‘Class A’ originally. It would have been well-known to Dick Denny and other proper electronics engineers that it wasn’t.

The proof that it isn’t is actually written on Denny’s original schematic for it, where it shows the cathode voltage as higher at full power than at idle.

I’m not sure when it was first described as ‘Class A’ - the first reference I saw was in Aspen Pittman’s book, which contains many other errors...

Voxman said:

I just said class A as 'coloquial' to indicate the type of tone it produces.

This is why it’s important to understand why it’s wrong.

The characteristic sound of this sort of amp is *because* it’s Class AB and *not* Class A. It’s that rise in the cathode voltage at high power which causes the compression we’re all familiar with. Class A amps do not do that, because one of their characteristics is constant current draw at any power.

Sorry, getting a bit off topic, but this does matter .

CHrisP86

Only played the amp for a few minutes when I picked it up but very impressed.  It was almost a 'sound in my head' moment which I think has baffled me most because it only cost £275!

Going to open it up this evening and give it a good clean.  Might change the speaker over as well and possible check on the bias, if I'm feeling brave...

@rico Thanks, will try your settings with my tubescreamer.

CHrisP86

I'm happy I know where the bias trim pot is and where the tester connections are.

How likely am I to electrocute myself?  Is there anything around these components that could do me any serious damage? 

ICBM

CHrisP86 said:

I'm happy I know where the bias trim pot is and where the tester connections are.

How likely am I to electrocute myself?  Is there anything around these components that could do me any serious damage? 

They're both on the main PCB near the power transformer end. The test connector is a white 3-pin jumper block - on this amp, both outer pins are wired together so if you don't have the correct connector lead, metering from the centre pin to one of the outers gives the reading. (On the DSL/TSL 50 and 100W amps, the bias is independent for each side of the power amp, hence the 3-pin connector.)

Yes, there are voltages which could do you serious harm around there. The trimmer is in a safer place nearer the front panel.

CHrisP86

Thanks @ICBM.  Might leave it to a pro in that case.

Where could I buy the bridge rectifier heat sink?

The tech I use is great, and qualified in electronics generally, but really only works on amps as a hobby so probably easier if I source the parts.