EH - Big Muff Pi ( Ram Head, Early Version )

guitarmongot · Post by **guitarmongot** » 24 May 2012, 20:59

Thats the version I buildt: V2-73 with NOS 5133 trannies : sounds great to me

I tried Skreddy Pink Flesh/Mayo and Rams Head/CivilWar/GreenRussian versions with
BC339C,BC550,2N5088 and a few others trannies (400-600 hfe) :
But I like V2-73 most : perhaps it´s the 5133 (350-450 hfe) that makes it so sweet??
/cheers M

bato001 · Post by **bato001** » 24 May 2012, 23:31

Kitrae wrote:Interesting. I never noticed much difference, if any, in using an electros vs a film caps, but I'll have to give it a try at C13.

It seems to make the greatest difference in Muffs built with low gain transistors. For example, the Swollen Pickle which uses a quad op-amp with an HFE of only 100. I switched the cap out in a Muff with 5088's and one with NTE199's and all that happen was the fuzz thickened slightly. I figure it is worth a try if he has already ruled out other circuit issues.

billgraam · Post by **billgraam** » 25 May 2012, 07:05

Tnx to all...I really appreciate your suggestions ... tonight i will try out various solutions, including the replacement (as recommended by a user in another forum) of the collector resistors with lower values (from 12k to 10k) to have, in the trannys q1,2,3 collector, 4.5 volts circa....
this my values:
q1) C: 4.03V B: 0.63V E: 0.03
q2) C: 4.11V B: 0.60V E: 0.06
q3) C: 4.13V B: 0.62V E: 0.03
q4) C: 4.66V B: 1.66V E: 1.20

bye...

bato001 · Post by **bato001** » 25 May 2012, 12:37

I finally figured out how to listen to your clip. Hmmm, I agree with Kitrae it sounds pretty high compression, big muffish already. The electrolytic will make your problem worse, not better.

If you want to open up the pedal a little and decrease the compression, you could try switching out the 914 diodes with LED's on Q2 and/or Q3, or increasing the limiting resistors between the gain stages from 8.2k to 10k or even 12k. play around with the base cap on Q1, decreasing the value robs the pedal of compression by decreasing the amplitude of the frequencies clipped later on.

billgraam · Post by **billgraam** » 25 May 2012, 17:34

Thanks, I appreciate the suggestions .. I'll try everything tomorrow ..
You think that the fact that in the collectors (q1,2,3) there is a voltage of 4.11, the transistors do work bad?
I must work around feedback resistors too?
bye

Electric Warrior · Post by **Electric Warrior** » 25 May 2012, 17:47

Vintage Ram's Head:

Electric Warrior wrote: Q1: C: 4.98V B: 0.65V E: 0.06V
Q2: C: 4.42V B: 0.67V E: 0.06V
Q3: C: 4.32V B: 0.62V E: 0.06V
Q4: C: 4.10V B: 1.54V E: 1.02V

Battery measured 8.99V

You're pretty much there voltage wise.

billgraam · Post by **billgraam** » 26 May 2012, 12:51

Hello everyone .. I thank you for the answers!!

I think I've discovered a problem in my ram's...
if you have the patience to listen to my little demo
http://www.mediafire.com/?81b0389b5so7c3a
you will notice that in the first part germandude plays a ram's true and acts with tone pot...
in the second part comes my ram's and when I act on the tone pot .. this works like a volume pot ... I think there could be a wiring or a pcb problem
I've used this pcb
http://www.mediafire.com/i/?xum9dww6uda13ad
.. can you tell if something is wrong?
I do not want to disturb ... I'm printing a different pcb, from Pawel of tourretboard.org
and probably i will use that for testing .. ..sigh..

bato001 · Post by **bato001** » 27 May 2012, 00:49

Double check your wiring. I have had the same issue more than once and it was a bad pot or reversed wiring in all cases. If you etched your own PCB, make sure that it is etched without cross bridges or eroded tracks.

billgraam · Post by **billgraam** » 27 May 2012, 10:52

I rechecked everything ... it was a cold solder on r23, from the sustain pot..
now my ram's sounds like this

I just have to debug the tone stack ... that does not work like in the video ..
I found an interesting post here a FSB
https://www.freestompboxes.org/viewtopic ... 27s#p99288
i hope this help every ram's hungry people...
tnx to all

billgraam · Post by **billgraam** » 07 Jun 2012, 14:27

UPDATE...
the tone pot problem was caused by a bad capacitor: C9 0.0039 uF
Now i've replaced this cap with another and the Ram's sounds GREAT...Im very happy...

tnx to all bye

bato001 · Post by **bato001** » 07 Jun 2012, 14:41

billgraam wrote:UPDATE...
the tone pot problem was caused by a bad capacitor: C9 0.0039 uF
Now i've replaced this cap with another and the Ram's sounds GREAT...Im very happy...

tnx to all bye

Excellent detective work!!! The real challenge to building pedals is trouble shooting a build that doesn't work properly. In a perfect world every pedal would work as soon as it is soldered up, but in the real world.......this happens very rarely for me.

billgraam · Post by **billgraam** » 11 Jun 2012, 18:02

Tnx for your help bato001

andregarcia57 · Post by **andregarcia57** » 13 Jun 2012, 13:34

hello how are you?
I am studying various ham's head!
which was exactly the model that David Gilmour used on The Wall album?
HAM'S HEAD V1 or V2?
the difference in c1 using 0.1 or 1uf?

thanks

andregarcia57 · Post by **andregarcia57** » 13 Jun 2012, 13:45

this version?

Kitrae · Post by **Kitrae** » 15 Jun 2012, 06:10

andregarcia57 wrote:hello how are you?
I am studying various ham's head!
which was exactly the model that David Gilmour used on The Wall album?
HAM'S HEAD V1 or V2?
the difference in c1 using 0.1 or 1uf?

thanks

If you find out, let me know

It is presumed he used his first Ram's Head Big Muff that Phil Taylor gave him in 1974, as he preferred that in the studio, but he also had the one Pete Cornish fixed up in 1976 that was in his touring effect board. We have never seen the inside of either one, so no one knows which version they were. There were 10 different circuit schematics used from 1973-1975, so it could have been any of them. I suspect it was the Violet schematic, first version.

andregarcia57 · Post by **andregarcia57** » 24 Jun 2012, 15:29

I'm riding big muff Ram's Head in PCB Madbean Mudbunny
as follows.

I tried using all 2n5133 transistors, more was a background hiss.
then I tried using all 2N5088 volume a bit low for my taste.

so I used 2N088 Q1 Q2 Q3 and Q4 2n5133, so the volume a little more fuzz and good.

any tips so I can better regulate BIGMUFF?
must have all transistors 4.5v?
grateful

R1 2M2 C1 100n D1 D4 1n914
R2 33K C2 470p D5 1N4001
R3 100K C3 100n Transistors
R4 470K C4 150n Q1 Q2 Q3 2N088 Q4 2n5133
R5 100R C5 470p Pots
R6 12K C6 100n SUST 100kB
R7 820 C7 100n TONE 100kB
R8 7k5 C8 470p VOL 100kA
R9 100K C9 100n MID jumper
R10 470K C10 4n
R11 100R C11 10n
R12 12K C12 100n
R13 7k5 C13 100n
R14 100K C14 100uF
R15 470K C15 100n
R16 100R
R17 12K
R18 33K
R19 33K
R20 390K
R21 100K
R22 12K
R23 3k3
R24 100R

andregarcia57 · Post by **andregarcia57** » 24 Jun 2012, 16:09

voltages

so I used 2N088
Q1 - 6,78v
Q2 - 6,97v
Q3 - 6,59

and Q4 2n5133 - 5,82v

andregarcia57 · Post by **andregarcia57** » 24 Jun 2012, 17:15

My big muff seems a bit soft.
is missing a bit of sustain.

MP3 BIG MUFF RAM'S HEAD
http://www.4shared.com/mp3/FUPepnj9/bigmuff.html

guitarmongot · Post by **guitarmongot** » 24 Jun 2012, 17:26

You should try 4xBC 239C (+600 hfe) I´ve used them for a more "modern" Big Muff sound:
also as mentioned before : if you put a compressor before Big Muff : it really comes to live:
more compressed,sustained fuzz.As fore Gilmour tone : he uses COMP-BM-OD-TUBE AMP:
A Big Muff has to be played LOUD to get that tone...IMHO.
/cheers M

andregarcia57 · Post by **andregarcia57** » 24 Jun 2012, 21:16

guitarmongot wrote:You should try 4xBC 239C (+600 hfe) I´ve used them for a more "modern" Big Muff sound:
also as mentioned before : if you put a compressor before Big Muff : it really comes to live:
more compressed,sustained fuzz.As fore Gilmour tone : he uses COMP-BM-OD-TUBE AMP:
A Big Muff has to be played LOUD to get that tone...IMHO.
/cheers M

yeah ok, I'll try again hfe transistors.

you got to listen to demo below?
Seems to be normal BM?
CHEERS

MP3 BIG MUFF RAM'S HEAD
http://www.4shared.com/mp3/FUPepnj9/bigmuff.html