Guild Brian May Power Booster(treble boost)

Belanger88 · Post by **Belanger88** » 07 Mar 2017, 06:10

is it just me or does this guild brian may pedal have far less components then the vero layout from tagboardeffects. Thanks for any input a head of time

Belanger88 · Post by **Belanger88** » 07 Mar 2017, 13:10

I think the difference is a cornish buffer in front of the one and this one uses slightly different cap values for a couple

Belanger88 · Post by **Belanger88** » 07 Mar 2017, 16:57

hopefully, someone will find these useful! I'll try to post good pics of the ts808dx next. I also have the amptweaker tight boost we could trace as a group but it's going to take a lot of help from some of you more senior members of the community as it's a lot to trace for sure

Manfred · Post by **Manfred** » 12 Mar 2017, 12:01

I made a PCB layout derived from the shots and found the schematic by tracing.

C6 is a guess following the Brain May Box.
http://www.next.gr/uploads/9/Guild_BrianMayBox.gif

I would say that the value of P1 shoud be a least 250 to 500 Kiloohms
How knows the real values of the original pedals?

Manfred · Post by **Manfred** » 12 Mar 2017, 12:11

The edit button did not appear.

Manfred · Post by **Manfred** » 14 Mar 2017, 00:04

I forgot the PCB-Layout.

Print the PDF-file using the original size setting.

GuildBrianMayBoostPCB.pdf: (6.71 KiB) Downloaded 328 times

smackoj · Post by **smackoj** » 14 Mar 2017, 05:05

I do not know for sure what the Brian May Treb Booster values are, but I know that I have built the General Guitar Gadgets version and it sounds great. I prefer the Brian May over the Dallas Rangemaster by far. So, if anyone wants to compare and contrast the schematic and values, here is a link to the GGG Brian May Booster. Their website would not let me copy or download the info so you'll have to follow the link. Sorry. http://www.generalguitargadgets.com/eff ... e-booster/

Manfred · Post by **Manfred** » 14 Mar 2017, 10:17

The Brian May Treble Booster has a input inpedance less than the Guild Brian May Box has.
The input circuit of the Box is a bootstraped common collector circuit, which provides a higher input impedance
I calculated it and found an input impedance of about 400 Kiloohms for a hFE of 200.
Therefore, I think a value range from 250 Kiloohms to 500 Kiloohms for P1 make sense.
Ultimately, however, only using trial and error bring the truth to the light.
In comparison to the other circuits result a value range of 4.7nF to 6.8nf fo C6.

Manfred · Post by **Manfred** » 14 Mar 2017, 10:52

PCB-layout with corrected trace width to 0,04 inch.

GuildBrianMayBoost2.pdf: (6.94 KiB) Downloaded 345 times

Belanger88 · Post by **Belanger88** » 14 Mar 2017, 18:07

Thanks, Manfred! appreciated, it may be cool to build into some preamp pedals as an option boost. I've going to modify the King Of The Britains to have a slightly more low end and then have this bad boy driving that

Belanger88 · Post by **Belanger88** » 14 Mar 2017, 18:13

if I had the pedal in hand I would verify the pot value's for you but I don't unfortunately I figured there are some pretty brilliant people on here tho and the circuit is really basic so someone could make sense of it

I'm pretty sure the cap in question is 6.8nf but I can't be sure either

LulaNord · Post by **LulaNord** » 31 Mar 2017, 18:47

Hi...as per my knowledge The input circuit of the Box is a bootstraped common collector circuit, which provides a higher input impedance.I calculated it and found an input impedance of about 400 Kiloohms for a hFE of 200.Therefore, I think a value range from 250 Kiloohms to 500 Kiloohms for P1 make sense.Ultimately, however, only using trial and error bring the truth to the light.

GAD · Post by **GAD** » 15 Jan 2019, 01:43

Hey there - I just joined because I'm writing an article on these pedals over on gadsguilds.com.

The reason you see a difference is because there were two different Guild Brian Map pedals. The red one in the OPs pics is from the 1980s. The one in the originally posted schematic is from the 1990s model.

HTH

The Rotagilla · Post by **The Rotagilla** » 15 Jan 2019, 19:16

I have the red and silver versions, what values you need?