Italian Jen Cry Baby - Drop in Volume and Bass when engaged

[52 Bill]

Though you didn't need to drag out your Cry Baby as there is a high resolution photo in my initial post if you scroll to the top of this page

Well as I have gotten older, I have lost my X-Ray vision and could not see through your photo to know what resistor was connected to what capacitor, etc.

I will respectfully bow out now and let your get on with your project. Best regards.

[sohosteve]

Hahaha!
Well at least a sense of humour still exists in these parts!
Oh the joys of not realising some of the exciting and mysterious machinations of a PCB...
Let me know your postal address and I'll send you a spare pair of X-Ray Goggles that I got from saving up old Bazooka Joe bubble gum wrappers. ;-)

Thanks again for all your sterling help Bill.
You came up trumps with my vintage script logo Dyna Comp AND Phase 45 - so I'm pretty sure your suggestions will sort my slightly lack-lustre Cry Baby.
You 'Da Man'!

Well as I have gotten older, I have lost my X-Ray vision and could not see through your photo to know what resistor was connected to what capacitor, etc.

I will respectfully bow out now and let your get on with your project. Best regards.

[Audiotexan]

As previously stated, I'm now starting to wonder. It may just be my failing memory playing tricks with me regarding it not sounding as good as I thought it 'had'.
It could well be because I'm using it with an amp that I'm less familiar with that has less pre-gain - so the sound is not so compressed.
Maybe the more distorted and compressed sound of my old amp masked the volume and tone drop - it is, as already mentioned, not huge, though currently noticeable.

It's always a good idea to have a 'base point' of reference when you're trying to modify tone circuits.
So playing on new gear and expecting similar sounds is shaky ground. If you get it modded to a sound you like (via the current undertaking -not talking volume drop here, talking 'bass response' mods)..then it may be bass heavy when you go back to the old gear... Just pointing out the obvious to be safe.

The innumerable posts on the web of other wah users with the self same problem lead me I believe that it could sound better. ie without a level drop when engaged. And with a little more 'weight' to the sound when rocked backward.

Well, part of the problem in this statement is that you reference two different things (for my intepretations at least). The level drop, and then 'weight' (which to me means bass/fullness of sound). Both are an easy cure, as long as you can interpret schematics, and follow traces as needed...(more below)
And even with traces, it's easy to sometimes get lost/confused (it can be a LOT to remember as you're tracking things down).

"Looks like you could change the first capacitor on the input side to a .1uF or maybe a bit larger to let more bass pass through the circuit. That's a cheap and easy" modification mentioned by a chap on another forum.

If I actually knew which was the 'first capacitor' I'd order a couple and try that - though I also have no reference point to know what beyond a .1uF I'd need to order to make it 'a bit larger'...

And that's what 52Bill was saying (as well as what I was thinking). Given that there's no location printing, and further compounded by the fact that we can't see traces (even if we could, it can be tedious...) it's at best an educated guess, in which cases, it can often be safer "just to leave well enough alone".
I know I'd feel *very* poorly if a piece of beloved/vintage gear got ruined as a result of advice that I offered (even if in the right spirit) if it was inaccurate/misunderstood/or even mis-applied. Annnnnyways...

Akin to the '75 MXR thread...I'm going to give you a pic with all the component values labelled.

<edit2> I was wrong on my note about the Ducati cap (and posted a corrected picture) being earlier vintage due to the fact that mine's a '69, and has the trash can inductor and has an EKT 4uf cap. Taking the Red Fasel and the Ducati into account, it has to be later vintage (72-73)! </edit2>

Hopefully, with this, you should be able to follow what 52Bill was talking about...while using the schematic (that's obviously -homedrawn-!) you listed above as a guide. Again though, you assume all risks, given the uncertainties that lie within!

Given how closely they match component-wise however, I feel 90% safe to say, that you should be able to change the 68k (as there's only one 68k, easy to find) to change the input level. (lower resistance = more signal getting through..however, you don't want so much that you clip the front end of T1!)

<edit>

The blue green Arco cap that is to the left side of the inductor (the big red round thingie that is marked FASEL), is the input cap. Try replacing that one with one that has a larger value than the original 0.01uF.

</edit>

*incidentally: the schem notes use of 5117's. Mine is an all original '69 Jen that uses 2N5232A trannies...so again, take that schematic with a grain of salt! As not only were there many revisions, but...who knows what inaccuracies could be hidden.

Hope this helps,
Audiotexan

[sohosteve]

[QUOTE=Audiotexan;350820]It's always a good idea to have a 'base point' of reference when you're trying to modify tone circuits.
So playing on new gear and expecting similar sounds is shaky ground. If you get it modded to a sound you like (via the current undertaking -not talking volume drop here, talking 'bass response' mods)..then it may be bass heavy when you go back to the old gear... Just pointing out the obvious to be safe.

Yep, this I understand fully - but the bottom line for me is that using either my hand-wired 18 watt clone through an original Palmer Speaker Sim or Di'd through my UA 6176 there is a noticeable drop in volume and low end (when the pedal is back - I'm fully aware that there's nowt but screaming highs with the toe down) and regardless of which reference point I'm using, I actually want it to work at a more constant volume at the very least. And hopefully with more 'weight' too.
At the moment I feel that I have cured the 'tone sucking' when it's switched out only to highlight that it 'tone and volume sucks' when it is switched in...
I have to admit that my prior use of this pedal has only been in a live situation through a cranked Marshall for solos where I'd also engaged a clean boost in addition to my Marshall Guv'ner and an old CS-2. So hardly surprising if I wasn't struck by the pedal causing a loss in lows and volume because the front end of the amp was getting such a kicking from the other pedals it would be almost fully compressed.
Even through my current recording set up the drop in volume and 'weight' is less noticeable when my Guv'ner is included in the chain - for obvious reasons! Though it is still apparent.

[QUOTE=Audiotexan;350820]Well, part of the problem in this statement is that you reference two different things (for my intepretations at least). The level drop, and then 'weight' (which to me means bass/fullness of sound). Both are an easy cure, as long as you can interpret schematics, and follow traces as needed...(more below)
And even with traces, it's easy to sometimes get lost/confused (it can be a LOT to remember as you're tracking things down).


Sadly, I can't follow a circuit diagram - though with the expert assistance provided so far I will be able to swap out the components that I've been pointed at with other values.


[QUOTE=Audiotexan;350820]And that's what 52Bill was saying (as well as what I was thinking). Given that there's no location printing, and further compounded by the fact that we can't see traces (even if we could, it can be tedious...) it's at best an educated guess, in which cases, it can often be safer "just to leave well enough alone".
I know I'd feel *very* poorly if a piece of beloved/vintage gear got ruined as a result of advice that I offered (even if in the right spirit) if it was inaccurate/misunderstood/or even mis-applied. Annnnnyways...

The only info I can see on the Ducati is 4/15 stamped on the end

I always take detailed photos of the before version so I have a 'map' to get me back to where I started from and as I have a solder sucker and a fairly decent iron I can remove components cleanly without breaking tracks.

[QUOTE=Audiotexan;350820]Akin to the '75 MXR thread...I'm going to give you a pic with all the component values labelled.

<edit2> Wholly incorrect note about the Ducati cap being earlier vintage due to the fact that mine's a '69, and has the trash can inductor and has an EKT 4uf cap. The Ducati has to be later vintage (72-73)! </edit2>

That is a huge help (I'm again stunned by the kindness shown here) and to assist other forum users who may need to fix the same problem I've stripped the pedal down again to provide this (flipped upside down only from the top side - ie NOT left to right as well!)

[QUOTE=Audiotexan;350820]Hopefully, with this, you should be able to follow what 52Bill was talking about...while using the schematic (that's obviously -homedrawn-!) you listed above as a guide. Again though, you assume all risks, given the uncertainties that lie within!

All risks are always mine in these situations and I take them gladly on a 'who dares wins' basis (not always how things turn out but for every one mess up or failed project I probably get about fifty positive results!)

[QUOTE=Audiotexan;350820]Given how closely they match component-wise however, I feel 90% safe to say, that you should be able to change the 68k (as there's only one 68k, easy to find) to change the input level. (lower resistance = more signal getting through..however, you don't want so much that you clip the front end of T1!)

<edit></edit>

[QUOTE=Audiotexan;350820]*incidentally: the schem notes use of 5117's. Mine is an all original '69 Jen that uses 2N5232A trannies...so again, take that schematic with a grain of salt! As not only were there many revisions, but...who knows what inaccuracies could be hidden.

Regarding the Arco - 1.06 0,010 / 10 is printed on it

You and 52Bill have both given me invaluable advice for which I am supremely grateful - apologies again for any lack of clarity caused by lack of technical nous or incorrect terminology.
Huge thanks!

[52 Bill]

Looking at the photo of the trace side of the board, shows what appears to be some cold solder joints. I would suggest re-soldering the board and see what happens.

[sohosteve]

Looking at the photo of the trace side of the board, shows what appears to be some cold solder joints. I would suggest re-soldering the board and see what happens.

I'll give that a go Bill - it certainly fixed the problem with the Phase 45!
Someone is sending me some components anyway but I'll try re-soldering before swapping anything out.

[Audiotexan]

Good eye on the cold-joints Bill!

Well, after having looked over a few more things...The true bypass wiring has some points that I'd do very differently, however, given that it's functional...I'm not kicking that dog while he sleeps lol

I've 'drawn' (ok, would ya settle for chicken-scratched?) out all the components on the trace side to make it easier to compare to the schematic above...as well as rotated it for easier side by side comparison to the component side view above, as if flipped to the right (comp. to foil).

Please let me know if you find an error. Accuracy is more important to me.
<Edit: Thank you to 52 Bill for pointing out my error on the TRACE view! -pic has been corrected, and the 33k is now properly oriented>


FWIW, some things definitely do not match up between this schem, and the unit SohoSteve has in hand.

Observations for contemplation
------------------------------
- the 4uf and the 100k appear to form an RC network to ground (tank tuning ckt). So that would account for the 'missing 82k' and it's actualy a 100k in this circuit. (I was thinking the 82k might be the one that's sometimes found to the left of the Fasel in the component side view).

<edit> Previous outstanding observations were contemplated, resolved, and redacted! lol


Not going to make any assumptions to transistor connections (eg: B,C,E) due to not knowing which exact ones are used in this example!

[Audiotexan]

Well sheesh. Hindsight being 20/20, I could have saved Bill having to dig out his trusty Jen...(and me doing the same) had I simply made the connection 'internally' that this was a damned 846. >.<

Amazing how nicely the circuit lines up now... (granted, this is a preliminary schem, and there are some minor variations, but much easier to follow now.)
Vox 846 wah (ca. 1967).zip

Also illustrates what I was saying before as to component simlarities vs circuit application (traces). lol


*anyone have any coffee strong enough to lift a two-day fog??*

[sohosteve]

YAY!!
My vintage Jen Cry Baby is now all fat and juicy and exactly how I want it!!
I can't thank you folks enough for bringing it to a level of full glory :-)

Well I tried the cleaning up of all the solder joints - tested it - sounded exactly the same - so the problem wasn't there but sensible to rule that potential headache out of the equation (though as already mentioned that tip DID sort out my inefficient Phase 45 without swapping out components - so definitely a good first port of call).
So I replaced the input resistor as suggested - BINGO! - no level drop between dry and effected.
I pressed on and replaced the cap and there is the missing bass!
Still got oodles of harsh screaming treble with my toe down but if I mute the strings and strum a 'chug' there's still enough drive in the low end to stop my G12H sounding like a Radio Shack 4".
So job done and I couldn't have got here without all the amazing suggestions and ultimately cures to my ills.
Apologies yet again for my lack of technical knowledge and poor terminology but hopeully this thread will help others to fall in love with their old Cry Babys (or Vox's - same thing anyway!)

Just before I go though - what did Audiotexan mean about the TB wiring?
Is there a better way to do it?
If so, please share.... :-)

[52 Bill]

I've 'drawn' (ok, would ya settle for chicken-scratched?) out all the components on the trace side to make it easier to compare to the schematic above...as well as rotated it for easier side by side comparison to the component side view above, as if flipped to the right (comp. to foil).
[ATTACH=CONFIG]29426[/ATTACH] [ATTACH=CONFIG]29425[/ATTACH]
Please let me know if you find an error. Accuracy is more important to me.

- the 33k is not parallelled to the 500mh choke (as drawn on the schematic).

I think that you have the 33K resistor scribbled in the wrong place. A close examination of the parts side photo shows it connecting to the 1K5 resistor, so it is paralleled with the choke, as it should be.

Most TO-72 are E-C-B with the flat side facing you.

[52 Bill]

So I replaced the input resistor as suggested - BINGO! - no level drop between dry and effected.

What value resistor did you use to replace the original one?

I pressed on and replaced the cap and there is the missing bass!

What value cap did you use to replace the original one?

Just before I go though - what did Audiotexan mean about the TB wiring? Is there a better way to do it? If so, please share.... :-)

Not sure what you are referring to, maybe AT will figure that out.

You have used what I refer to as the Fuzz Face total bypass circuit. It completely removes the input and output from circuit loading and it grounds the input of the effect circuit to reduce the possibility of added noise or oscillation.

The more common version of total bypass does not include the grounding of the effect circuit input. Personally I prefer the FF circuit especially when working with high gain circuits.

Congrats on getting it working again.

[Audiotexan]

First and foremost:

Congrats on getting it working again.

Seconded!! =D
And well done sir! Glad you're happy with the results!

I think that you have the 33K resistor scribbled in the wrong place. A close examination of the parts side photo shows it connecting to the 1K5 resistor, so it is paralleled with the choke, as it should be.

Assuming you're talking about where I've outlined in red circles:

Great catch!! I had to put them even closer before I saw what you meant. (I had a nagging feeling something still seemed amiss.. Kinda like Dr.Gonz said in another thread, I should've known better than to trust my gut. lol)

I'll update that post (and pic) with a revised version in just a bit!
(since invariably, when someone comes along later, they may save the first thing they see, not reading further to learn that it's actually in error.)

Most TO-72 are E-C-B with the flat side facing you.

*nods* ...but given how many other uncertainties were looming, and the fact that I've seen BC109B's (metal can), 2N5232A's ('faced'), and one other (completely round head -non can) that I can't recall ATM, in the Jen v846 circuit, I didn't want to make any 'leaps'.
(Though I know that most USA trannies in a given time frame rely on the same pinout, and it would probably have been perfectly safe to put those in... But my normal approach in forums *technical forums especially*, I TRY to tend to lean towards 'safe mode' rather then shoot off the cuff, but even still, 'the cuff' rears it's head sometimes. :x)

Perhaps, if Steve can let us know what trannies are in his, I'll update that pic on a final version, and post it with all labels.

What value resistor did you use to replace the original one?

What value cap did you use to replace the original one?

I was curious about this as well. =)

Not sure what you are referring to, maybe AT will figure that out.

You have used what I refer to as the Fuzz Face total bypass circuit. It completely removes the input and output from circuit loading and it grounds the input of the effect circuit to reduce the possibility of added noise or oscillation.

Well, I had mentioned I was going to leave sleeping dogs lay (so to speak) in regards to the TB method/wiring he used... but I decided against opening that can of worms. Since it was working at that point, and I didn't want to complicate matters any further for him. Didn't want to risk sending things "off track".

The more common version of total bypass does not include the grounding of the effect circuit input. Personally I prefer the FF circuit especially when working with high gain circuits.

That's another part of why I left it alone, there's several ways to do a bypass. Some simple, some more in depth.

But since he got it to where he likes it, and in good working order, I'll go ahead and elaborate a little.

What I typically regard as true bypass is taking the entire thing out of the circuit (3 targets: switching the signal, ground, and battery). With an option for an input shunt to ground in bypass as an added 'safety'.

I've always used the center pins of the switch as the 'source' entrance/exit points (items to be switched/manipulated), with the outside pins being used for 'options' (switch routing).

Given that appearances indicate his 'green wire' is the signal input, he went to an outside leg on the switch, and the 'black wire' from the switch to the board signal input. (simple reversed wires -but if he changed them, he'd have to rewire further to account for the input shunt) So it was no biggie on that one.

Another was that his wiring method didn't switch the battery, or ground (which currently relies on chassis at the output jack, but has since factory). Which again, are not big issues, it's just different from what I would do!

No harm, no foul, just different!

There's an old addage: "If it ain't broke, don't fix it!"
Since it's working, and like you like it, I wouldn't change a thing Steve! And again, congrats on getting it where you wanted it! =D

Besides, sometimes if you do Vs switching, you then have to modify the circuit even further to eliminate 'pops' from the initial surge when B+ is applied from the switched position. As above, if you're happy and it works as desired...don't 'fix' it! (REGARDLESS of "how I'd do it". lol)

[sohosteve]

Hi chaps
Thanks again - and apologies for my omissions - DOH!

Please bare in mind that I'm not tech savvy so these may include brand letters!
The components were supplied (very kindly) free of charge by someone I purchase project (bud box style) boxes from and were the closest he had after requesting to buy the values of components suggested by 52Bill, with him knowing that these were to compensate for volume and bass drop in a Jen Wah post TB mod.

The replacement cap says 2A104J
The resistor is a 330 (if anything, this makes the signal a smidgeon louder than dry but keeps the signal to a much closer level than with the original component)
The transistor in the bottom right of my photo reads (I believe - though it runs around the thin 'skirt' and is very difficult to read {even with a magnifying glass} as the characters are smudged and fall off the edge in places) STP5172
The transistor below the Fasel reads 2M3416 (it could be 2H or 2N - the characters are smudged)

Hopefully you will be able to decipher any errors in these values between you.

[sohosteve]

First and foremost:

No harm, no foul, just different!

There's an old addage: "If it ain't broke, don't fix it!"
Since it's working, and like you like it, I wouldn't change a thing Steve! And again, congrats on getting it where you wanted it! =D

Besides, sometimes if you do Vs switching, you then have to modify the circuit even further to eliminate 'pops' from the initial surge when B+ is applied from the switched position. As above, if you're happy and it works as desired...don't 'fix' it! (REGARDLESS of "how I'd do it". lol)

In that case I'll leave it as is but appreciate the heads up :-)