Eric Tessmer - Wah Pedal Upgrades - Pt. 2: Transistors & Inductors

Finished out rejuvenating Elliott's old wah pedal with some zesty transistors and a tweak to the vocal resistor. Tried it out with a bunch of different inductors as well.
Check out Elliott's Instagram profile @elliottbrown_6 and give him a follow and listen to what he does with the pedal.
Please note: filming the parts while auditioning wah components is very difficult, especially the overhead shots while varying the vocal resistor, since many differences are subtle and many of the changes I made today could best be said to change the feel of the pedal and its sensitivity. Watch the travel of the pedal and how tight the sweep is or isn't in relation to the sound. This video is mostly to show you how to do this to your own wah, since there's no universal 'right answer' for all wahs.
PS: Recent studies show that only extremely attractive people like videos like this. Subscribers to this channel were described as 'nothing short of breath-taking'.

[@killingmasheen]

Awesome video. The only thing I would want to know is the DCR of those inductors because the lower the DCR, the higher the internal Q-factor. Inductor impedance is a fairly critical factor in many applications like graphic EQs where ideally you want each inductor to have the same DCR so that each Hz band boosts/cuts equal to the other. On the opposite end of the spectrum high impedance inductors work well when you don't want to lose too much signal going through it, the Gibson Vari-Tone circuit is a good example. I remember doing a version of the Dawk Stillwell MTC circuit (a Ritchie Blackmore mod) in my strat using a super high-Q toroidal inductor from a Mesa Boogie graphic EQ and the signal level dropped to near nothing when the pot was zeroed out. It was a 1H inductor so it wasn't a small one but the DCR was about 60 ohms. What I did instead was wind my own inductor around a metal screw with washers on each end with a few thousand turns of 42AWG wire. It came out at 1.2H with a DCR of like 2.5k and it worked like it was supposed to just cutting the midrange.

[@LawGone1]

Great video my man

[@marij78tex]

Thanks for this video Eric! Gave me the Info I couldn’t find anywhere else 🤘🏼

[@ppa6964]

Awesome, best wah video in youtube, very helpfull, the Q resistor makes the bigger difference to my ears.

[@Curtislow2]

The sweet spot you refer to reminds me of my surfing days trying to stay up!

[@JSTN_C]

new favourite channel!

[@erictessmerband]

Glad to have you along!

[@MattsGarageMiscDIY]

Another solid video, Elliot is going to be stoked.

[@buddybeetle]

Excellent- very interesting, and I like your presentation style.

[@ScottyBrockway]

The emitter resistor on Q1 makes the most difference, you can stick a 1k pot in there and mess around with it to see how it affects the gain and range.

[@wecandisarm]

So friggin in love with this and all the content!

[@scottphillips161]

Another great video. Been digging EP2 a lot lately, by the way.

[@mikecamps7226]

ok.....I was trying to follow you in the fast forward video to determine on your spec sheet for the readings......as to which reading represented which transistor position...the Q1 & Q2 in the standard schematic...since you did not note that on the white sheet....... I'm an old school tube guy.....my father was an RCA dealer and think about going in to business in 1935 and the electronics experience along the timeline......when we did our own service for the products we sold in the dealership.......and....the RADIOTRON MANUAL hahaha......some snobs don't understand that. SO I am old but not ancient.....and if my Dad were still alive...he'd be like 106 years old. SO I know what is MYTH in MUSIC JOURNALISM and it amuses me what the Gospel followers thus believe....just saying ! When I first started college for engineering.....they had the machine at the state branch campus I was at...that we could make an IC ....the wafer and doing the layout etc......and how much actual circuitry is in a generic IC when its depicted as.....a triangle with an output and 2 inputs of opposite polarity. But being said, yes...sockets hahaha......and "finding" musical chips for a particular circuit......while NOT PAYING ATTENTION TO SPEC SHEETS. Lets just say I have a disdain for TL072 IC's in circuits where .... the choice.... was made based on the engineering data sheet. BUT ya.....each transistor needs the MUSICALITY TEST.....and at times its about WHO MANUFACTURED the part ! AND NO its not the JRC 4558 thing with tube screamers hahaha.....EVERYTHING is peculiar to particular circuits. A Blue Printing for a recipe is NOT always a wash rinse and repeat scenario.....I'm sure you know.....hahahaha. BUT as one of the big things with the musical snobs who play guitar REALLY LOUD.....FOR MANY YEARS.......better get your ears checked and graphed as.....everybody gets old and things...change hahaha.....what one person HEARS...might not be what another is capable of HEARING.....IF we are only talking...symmetrical hearing but don't expect Symmetric is the RULE with EARS.......and thee generation of EAR BUD users and Headphone people. My gf of many years I live with....who actually went to WOODSTOCK and thee original event.....is getting hearing aids at her age.....and I'm still good & I shoot guns hahaha other than music. I'm due to go get graphed just to determine a base line. I hate getting in our car.....after my GF has been driving...and...has adjusted the radio while she was riding around......ummm I have a......different ....EQ..... for the radio...know what I mean....... But with me and having dealt with customers over the years in our family business growing up......my clients and critical EARS & sensitivity.....and communicating.......I'm about to require hearing tests to qualify clients hahaha......much the same way the KLON guy did an interview before building you a KLON back in the day when he charged $300/$400 and it was MAIL ORDER in thee pre-internet days......you have to be proven WORTHY hahaha, but I need to determine handicaps for the musical golfers...know what I mean...... BUT I must mention, as first time viewing your content and your demeanor......I LIKE YOU

[@bsibille]

Thanks for sharing Eric!

[@stevengonzalez4957]

Man, I really dig these vids!! Thank you, Sir!!

[@ducttapewalker4834]

You can also put a dual pot in a box and measure the ohms live while testing on the second set of leads

[@erictessmerband]

Ducttapewalker good point! Didn’t have one on hand.

[@qddk9545]

That might be a very bad idea. Most pots track very badly, so you can not count on what you read.

[@brettwood1091]

just wanted to say that I got the 69th like - and I think that means something killer insights Eric, appreciate it - and enjoying your music now that I found u here on stalk tube keep doing your thing mate, from Australia

[@jerryyeaaah15]

that second set of transistors are amazing! What are they!

[@codycaporale5443]

I’ve got an old 67 bandmaster that maybe you could run through I forget who use to own it but he wants it back

[@RickDanner]

hey saw you in guitar world magazine awesome !

[@Shadytube2024]

I have a trashcan wah that sounds a bit weak. What usually goes awry on these? Should I check any specific resistor or cap?

[@mikejamieson4252]

2nd set best, did u try some bc109b’s?

[@MojoMedicineMan]

Got a transistor question for you. Where's a good source?

[@PANOPTIC-VIDS]

That is the coolest shit right there and thank you!!! Hush now!!

[@brettwood1091]

Did anyone else spin out at the the obvious thickness as soon as the original transistors were swapped in the chain? Scary! That’s the stuff that can actually frustrate the shit out of you if you pay 2k or more for an old Clyde and it sounds like example 1 of this tranny test. The levels that Eric is sharing is greatly appreciated, and he’s right Nik Sevigny is also a sevant of how to’s with regards to classic gear and tones.

[@richardm2855]

Hey Eric! Awesome video and some great information with audible examples. I have a question for you...I just got myself a Vox v847a (seller mislabeled as v847) and I was wondering if there are any mods you would recommend to unlock this pedal’s potential. Right now true bypass is the only thing fairly quick and easy but I’m open to your suggestions. Last resort would be to gut it and rebuild but that’s costly. Thanks in advance.

[@ALtheDoctorWho]

To my ears the second set sounded the best.c];-)

[@waynegram8907]

The transistors should both MATCH which HFE value?

[@qddk9545]

No they should not, the first stage is an amplification stage and the other one an emitter follower. Matching makes no sense. Actually it may only make sense to experiment with Q1.

[@lucasplowman3245]

Now this is the kind of tonal insanity I can get behind

[@pietroanania]

hello how I can eliminate the ssh noise www.electrosmash.com/vox-v847-analysis using the AC/DC adapter in the wha 847?It increases with other effects as distortion and others in the chain. It is possible put 1000 pF ceramic capacitor filter between the power positive input of adapter and the mass (negative) of the pedal? I provided that stabilized power supply and the rest is good. I'll wait your valid suggestion with a schematic diagram. Regards

[@theriffwniksevigny5473]

“You ever seen a ghost”

[@erictessmerband]

"You wanna BE ONE!!!"

[@6stringmyles]

Level of geekery = 💯

[@buckinjb]

"Fiideyliin" LOL.