Bluesmaster pre with non-hrm overdrive

[da Geezer]

Here's the updated schematic of my cathode biased version.
It's really more "tweed" in the power amp, with significantly lower cap values & lower volatges due to the 5U4 rectifier.
All modifications are in red, as well as voltages & notes.
One "major" thing in the OD section....I didn't have any 100kB pots in stock, so I used all 250kB instead (glad I did!)

I've built a lot of amps, but this one is the best so far for my tastes & needs.

Also, here are some notes on the sound clip I posted:
Guitar=HSH Strat
Speaker/cab=Weber Sig12 Ceramic (1st issue, ~2003?) in a 1x12 open back cab
Kleinulator in the amp loop, Digitech verb & delay in the K-lator loop

Geezer

EDIT: Corrected valve of bias resistor (to 250R) and labeled 5U4GB rectifier

[10thTx]

Sound clip has great tone! Thanks for sharing the schematic. It is appreciated!

With respect, 10thtx

[guitardude57]

That is a really nice sounding rig! Good job Brother.
Probably just loud enough to feel it well........and mics well.

[erwin_ve]

Geezer; awewsome sounding amp! Nice playing too. I was a bit worried about your big master bright cap. But it's just right in your clip.
Thnx for sharing the schematic!

Erwin

[martin manning]

Here's the updated schematic of my cathode biased version.

Some schematic corrections: the power stage cathode resistor is marked 250k; maybe label the rectifier as 5U4 too.

Some verrry nice tones there!

[da Geezer]

Here's the updated schematic of my cathode biased version.

Some schematic corrections: the power stage cathode resistor is marked 250k; maybe label the rectifier as 5U4 too.

Some verrry nice tones there!

Corrections done......

Thanks Martin!

[10thTx]

IF someone is interested in an editable ExpressSCH version of Geezer's schematic, you can find one here:

http://www.el34world.com/Forum/index.ph ... 7#msg98577

With respect, 10thtx

[Drumslinger]

erwin/Geezer,

nice sounding amps guys. very nice. very smooth and melodic. excellent build!! were these 50W builds?

[da Geezer]

erwin/Geezer,

were these 50W builds?

Mine is 50w.......I think Erwin's is 100w(?), at least that's what he shows on the schematic.

Geezer

[Steven_nl]

Hi guys

I picked up my amp. Erwin customized it for me after I had bored him to death with my rantings of wanting a Bluemaster clean channel and an OTS OD channel.
He did an awsome job. You heard his clip in this topic.
I have had the amp only a few days and I didn' t want to p*** of the naighbours to much on account of Christmas but I'll gice you a short impression. Keep in mind I couldn't A/B it with the orginal non HRM 50W OTS

I use a serial Dumblelator (made by Erwin) and a cab with 2 G12-65's.

The amp sounds rounder, warmer and less "in your face". For me it has less of a Twin Reverb (cold) type of sound. Maybe the string seperation is not as good as the original (minor), but it does have a nice sparkle.
It also sounds nice with the MV bright cap engaged (67pf) but I don't realy like that on the OD. It adds a buzz on top I don't care for.

I also think this amp has a nice " bloom" to it. I hope I'm using the right term here, but what I mean is that the amp has a great sustain and soemtimes it seems tp get a bit louder almost into feedback after you hit the note.

I have been experimenting with the master volume and the return of the Dumbleator (which I usually use as Master) I have the impression his helps brightening up the sound a bit.

Overall I'm very happy.
A special thanks to Erwin who is a great guy and a excelent technician.

Steven

Ps the PAB switch now works well. No nasal boxy sound any more.

[Structo]

Glad you like your new amp.

There are a couple ways you can address the bright cap.

You can use a relay to switch the cap into the circuit on clean only and off when you are in OD.

The master volume bright cap is to compensate for the Dumbleator so you may need to adjust the value of that cap to something smaller if it is too top heavy for you.

[Steven_nl]

Hi Tomn
Yeah we did try 47pf. but strangely enough that seemed to have no impact at all. That was before Erwin changed the pre-amp though.

[erwin_ve]

Hi guys

I picked up my amp. Erwin customized it for me after I had bored him to death with my rantings of wanting a Bluemaster clean channel and an OTS OD channel.
He did an awsome job. You heard his clip in this topic.
I have had the amp only a few days and I didn' t want to p*** of the naighbours to much on account of Christmas but I'll gice you a short impression. Keep in mind I couldn't A/B it with the orginal non HRM 50W OTS

I use a serial Dumblelator (made by Erwin) and a cab with 2 G12-65's.

The amp sounds rounder, warmer and less "in your face". For me it has less of a Twin Reverb (cold) type of sound. Maybe the string seperation is not as good as the original (minor), but it does have a nice sparkle.
It also sounds nice with the MV bright cap engaged (67pf) but I don't realy like that on the OD. It adds a buzz on top I don't care for.

I also think this amp has a nice " bloom" to it. I hope I'm using the right term here, but what I mean is that the amp has a great sustain and soemtimes it seems tp get a bit louder almost into feedback after you hit the note.

I have been experimenting with the master volume and the return of the Dumbleator (which I usually use as Master) I have the impression his helps brightening up the sound a bit.

Overall I'm very happy.
A special thanks to Erwin who is a great guy and a excelent technician.

Steven

Ps the PAB switch now works well. No nasal boxy sound any more.

Hi Steven, thanks!
I'm glad you like it. It was a real challenge for me and the outcome was a pleasant surprise.
About the bloom: I played with the PI trimmer.

[mat]

I made a little record showing the capabilities of the Od channel.
Played with a strat.
http://soundcloud.com/erwin_ve/room335

ervin_ve, great sound and playing, really good. Could You share Your recording setup ? I'm such a novice on that. Would be very nice to get that high quality sound to my recordings.

Thanks for the clip,

[erwin_ve]

I made a little record showing the capabilities of the Od channel.
Played with a strat.
http://soundcloud.com/erwin_ve/room335

ervin_ve, great sound and playing, really good. Could You share Your recording setup ? I'm such a novice on that. Would be very nice to get that high quality sound to my recordings.

Thanks for the clip,

Thnx for listening! Setup was: Shure SM57 into mic pre-amp Eleven Rack into ProTools8. Mic position was like this(thnx to massygt6); [img685]http://img713.imageshack.us/img713/2370/29731759.jpg[/img]