VYPYR "Volume Sponge Mod" + !!! "Volume Pedal Mod" !!!

A forum for discussing the Vypyr series amplifiers, Sanpera footswitches and share settings
GRE2608
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Joined: Mon Jun 18, 2012 3:07 pm

VYPYR "Volume Sponge Mod" + !!! "Volume Pedal Mod" !!!

Post by GRE2608 » Mon Jun 18, 2012 4:24 pm

Hello guys!

As the loudness of the VYPYR30 has been widely discussed (and bothered many as they wanted it for bedroom use as well) I decided to have a go and try to operate on the little thing.

Though not clear at first and having spent quite some time playing with pots and resistors I came to realize that the volume pot of the VYPYR30 is actually a voltage divider. Eureka!!! The rest fell into place quite naturally and I am sure it might already be ringing a bell to you too.

The way I did it was by adding an extra 20K Log pot, re-route the incoming signal (red) into that new pot and then (now reduced) return it back to the original "B20K" volume pot. This way you subdivide the main volume range to a chuck that is useful to you. E.g. if you set the 20K Log pot to limit at 20% output, the front pot (original amp volume pot) will range between 0-20% etc. From what I understand by reading several forums and testing this mod, it should behave even better than the "Power Sponge" of the VYPYR75.

The obvious advantage is that you don't drive your amp hot compared to standard commercial attenuators connected between the amp and the speaker. Nor you loose any sound quality, considering that you don't effect the audio output but only the volume level.

On the contrary, it provides you with a very fine volume adjustment for your required range so you can now make !-real-! use of pre-gain and post-gain adjustments at bedroom levels, without having to painly re-adjust the volume at 0.05~0.10% intervals. This way you can get your desired tone and volume results as easy as you would for very loud levels.

I have attached the wiring schematic which I think is very easy to follow. Still, let me know if you need any help.

That's all folks! I hope this little mod proves useful to all of you VYPYR30 fans.

Best regards to all,
GRE2608

---

Note 1: I am not sure if anyone else has already provided this or a similar mod, so take it easy if I came second.

Note 2: I used a log pot for finer low end adjustment. Feel free to use log or linear according to your taste.

Note 3: I installed the extra pot at the back of the electronics enclosure as I didn't want to alter its face and also because after setting your required range, "typically", you don't need to mess with it very often, so it's better if its out of your way. Obviously you can install it at any position convenient to you.

Discalimer 1: Your mod = Your problem. Verify my design as well as your skills before modding.

Discraimer 2: My mod = My mod. You can obviously mod your amp either for personal or commercial use; no questions asked. You can publish this mod on another forum or any other personal or commercial website/media, provided you supply a link back to this post or reference it by "GRE2608".
Attachments
VYPYR30.VS.MOD.PNG
VYPYR30.VS.MOD.PNG (40.81 KiB) Viewed 19037 times
Last edited by GRE2608 on Fri Jul 27, 2012 3:23 am, edited 7 times in total.

GRE2608
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Re: VYPYR30 Attenuator - "The Volume Sponge Mod" - Eureka!!!

Post by GRE2608 » Thu Jun 21, 2012 4:35 am

Hello again guys!

Here are some images from the mod. For my own VYPYR 30, I replaced the volume pot with a standard market 22K pot, so I am including the schematic for your reference.

BR,
GRE2608
Attachments
This is the overview of the mod.  As you can see all you need is an extra 22K pot and 3 wires.
This is the overview of the mod. As you can see all you need is an extra 22K pot and 3 wires.
overview.jpg (254.29 KiB) Viewed 18988 times
"Attenuation" pot inside view.
"Attenuation" pot inside view.
att.pot.jpg (238.7 KiB) Viewed 18988 times
"Attenuation" pot outside view.
"Attenuation" pot outside view.
att.adj.jpg (231.25 KiB) Viewed 18988 times
Volume pot inside view. (As mentioned I have replaced the original pot)
Volume pot inside view. (As mentioned I have replaced the original pot)
vol.pot.jpg (193.16 KiB) Viewed 18988 times
Volume pot outside view. (Everything kept as original design.
Volume pot outside view. (Everything kept as original design.
vol.adj.jpg (216.01 KiB) Viewed 18988 times
The is the wiring diagram for replacing the B20K pot with a market pot.
The is the wiring diagram for replacing the B20K pot with a market pot.
wiring.market.pot.jpg (92.16 KiB) Viewed 18988 times

guitarman1phil
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Posts: 110
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Re: VYPYR30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by guitarman1phil » Thu Jun 21, 2012 10:51 am

great work, thanks for the pics


Phil

schmidm2
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by schmidm2 » Sun Jul 15, 2012 12:10 pm

Thanks for the mod info. Looks great and I'm going to give it a try. I'm fairly new at amp mod/repair and brand new to forums. I did replace 2 pc mount pots (volume and gain) on my old amp and brought it back to life. My son loves it. Where can I get the pots you used for this mod. I've looked all over online. Found very few 22k and they were all pc mount.

GRE2608
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Joined: Mon Jun 18, 2012 3:07 pm

Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by GRE2608 » Mon Jul 16, 2012 12:53 am

Hello schmidm2,

to be honest the ones I used are just standard pots off a local electronics shop for about 2 EURO each. :roll: The PC mount pots will of course be of better quality and you can always solder the wires on them one way or another.

As mentioned in my previous posts I recommend that you leave the original volume pot as is and add only a second pot at the rear. This way you won't have the trouble of refitting the shiny front pot cover on an aftermarket pot.

Try www.mouser.com and go to Passive-Components > PotentiometersTrimmers-Rheostats > Potentiometers. Then filter for 20 kOhm pots and find something that you and your pocket like.

Still, I'd recommend that you don't bust yourself and just use something that is easily accessible from a local shop. At the cost of pots today, shipping expenses will be a lot higher than the pots themselves.

Best of luck and let me know if you need more help.

PS. I would appreciate if you post your results and some photos when your mod is done and you are happy with it.

schmidm2
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by schmidm2 » Wed Jul 18, 2012 6:28 am

GRE2608,

Thanks for all of the info/advice. I'm hoping to do the mod this weekend if I can break away from work long enough to get the parts. I bought the amp for nothing more than a toy. And I love it except for volume issue.

So I'm leaving front volume pot. No need to add work and risk messing up the face. I'm putting the new pot on the back. I'll take lots of pics and let you know how it goes.

schmidm2

misterdetail
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by misterdetail » Thu Jul 19, 2012 3:39 pm

Not to take anything away from your cool Mod but can't something similar be accomplished just by lowering the Post Gain? This is what I do on my Vypyr 30 and I almost always play at bedroom volume. I set Post Gain no higher than noon and Master Volume at 1 to 2, which doesn't drive my wife or kids nuts. Sounds good to me and no worries about voiding the warranty by doing a Mod.
Peavey 6505 Piranha

"For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord."
Romans 6:23

bhsbhswarp
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by bhsbhswarp » Thu Jul 19, 2012 6:33 pm

i keep the post almost barely on and turn the master up.thickens it up nice at bedroom volume
"You can't fix stupid"

GRE2608
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Joined: Mon Jun 18, 2012 3:07 pm

Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by GRE2608 » Fri Jul 20, 2012 1:30 am

Hello misterdetail & bhsbhswarp and thank you for your comments.

The real purpose of post gain is to aid in "balancing" the volume output between presets (as it is included in the saved parameters of every preset) and not to provide master-like volume control. This is mainly because each stomp/amp/effect alters the final volume output. In the original configuration, some combinations still sound quite loud even with post at the minimum level and most importantly the Master is too loud for most of its range from 1,5 upwards.

The "Volume Sponge Mod", allows you to split the volume range between the added second pot and the master vol, providing better master pot resolution. i.e. if the second pot (which is first in the wiring path) limits the volume to e.g. 30%, then the master volume explores this remaining 30% between 0 and 13 providing not only bedroom levels but even "night bedroom levels" with the same setting without effecting the ability to use high gain for good distortion, nor forcing you to loose the purpose of post gain for balancing the volume between different presets.

As such, after setting the extra pot to about 30% you get night bedroom levels at 1~7 master volume and bedroom level at 8~13 master volume, making the whole range of the master volume usable. Respectively you can set it to e.g. 60% to get bedroom levels at 1~7 and higher practice levels at 8~13 etc etc. Finally, set the extra pot to 100% and have your master behave as the original setup for jamming or gigging. :D

I know that a mod is not everyone's bread and butter, but considering the results this mod has a very high "value for complexity" ratio with a truly minimum risk of messing it up. Having it for quite a while now I have never looked back and couldn't be happier with the result. I hope schmidm2 will provide a +1 pretty soon and I would also appreciate if any of the gurus/admins/moderators would make their comments...

Best regards to all!
Last edited by GRE2608 on Fri Jul 20, 2012 5:35 am, edited 1 time in total.

Lord High Warlock
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by Lord High Warlock » Fri Jul 20, 2012 3:20 am

Is there a way to convert the Power Sponge on a 75 to this kind of Attenuator?? That's the only feature on my 75 that I'm not really happy with, and I would love to have it do what your mod has done for your 30.

Thanks! :)
- Warlock/LHW/Rich

Guitars
2011 Gibson Les Paul Studio '50s Tribute
2015 Epiphone Masterbilt DR-500MCE
2016 Peavey AT-200
1964 Goya F-27

Amps
Peavey Vypyr Pro w/ Sanpera Pro
Marshall AS100D & MG10cd
VOX Valvetronix VT80+

GRE2608
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Joined: Mon Jun 18, 2012 3:07 pm

Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by GRE2608 » Fri Jul 20, 2012 4:02 am

Hello Lord High Warlock,

I am glad you like the mod and I'm more than happy to help you out.

To my understanding, it is 99% possible since this mod is really a "patch" style mod over the standard volume pot. For the 75 you could even use the original Power Sponge pot instead of installing an extra pot.

At the same time I would prefer to have a look at the wiring diagrams of the 75 before confirming 100% the mod compatibility and also check the specs of the Power Sponge pot to confirm suitability as the "attenuator" pot. Since I am a bit tight with time you can try to locate the schematics and post me their links or attach them on the thread so I can check them out in detail.

BR,
GRE2608

GRE2608
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by GRE2608 » Fri Jul 20, 2012 5:24 am

Hello again...

Well, patience is obviously not "my" virtue... Whats 'time' compared to a challenge...

Ok, here we go.

I looked up this website which has the schematics I used for my mod.
http://zorkmids.com/wordpress/?p=384

Unfortunately, it only has the amp schematics of the 30 and 60 but since they are both using the exact same volume wiring, I am sure the 75 is most likely the same as well.

This image from the same website shows the 75s internals.

Image

All in all this image shows that the volume wiring and pot of the 70 looks (at least) exactly the same as the 30 and the 60. Now, as I have not found the 75s schematic I still cannot confirm the specs of the Power Sponge pot. Respectively, I can offer you two options:

A. (Easier) Open up the amp, remove the Power Sponge pot from the face, adjust it to full power and secure it inside ensuring it is also fully insulated. Wrapping the whole thing nicely with some electricians tape should do the trick. :D You then install a new "Volume Sponge" pot and wire it according to my schematic. Lastly, if you care for appearance, custom fit the nice and shiny pot knob that you removed from the Power Sponge during removal onto your new pot.

B. (Harder) Open up the amp and measure the Power Sponge pot as to help me understand if it can be used for our "Volume Sponge" pot purpose. If compatible with our purpose, we should then create a "bypass" over the Power Sponge cables (now removed from their pot) as to provide us with full power (I'll give you detailed advise on this later on if you decide to go this way). Lastly rewire the Power Sponge pot as described above to make it into a Volume Sponge.

That's about it. I hope its all clear although I am always here to give you more help. Let me know which option you'll go with and if you need anything else to be clarified.

Good luck and I await your photos and comments on the results.

BR,
GRE2608

bgh
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Location: Northeast Tennessee

Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by bgh » Fri Jul 20, 2012 7:17 am

GRE2608,

If I understand everything correctly, your mod pretty much expands the 'master volume' to be a 2-pot setup, with the range of the original master volume pot now being regulated by the new pot. The mod would thus provide a (much) more granular control over the master volume pot, correct?

If so, pretty cool.

If you want to do this for a 75, you may want to consider leaving the 'Power Sponge' alone. According to the Vpypr manual, the 'Power Sponge' on the 75 and 100 is not really associated with the master volume pot. It seems to act like a governor to the or limiter for the transformer.

I'm not really sure how usable this feature is on a solid-state power amp. Historically, most solid-state amplifiers have no need of attenuators.

Does Peavey use its Trans-Tube logic within the power stage, or only the pre-amp stage? If it uses it in the power stage, then cranking the master volume on a solid-state amp would achieve different levels of simulated power tube distortion.

It is a feature that I wish had been on the 60 and 120 tube models. Can you imagine having been able to turn the sponge way down and the master volume way up - push those 6L6s and get some power tube distortion at a volume level that doesn't fry household pets at 50 yards.

But, concerning the granularity of the master volume pot, you may be on to something really neat. I know with my tube-60 that every so often I hit a situation where the post-gain setting I choose is just high enough to make the setting of the master volume rather touchy - a smidgen one way or the other really impacts the volume.

Anywho, very cool work!
Lefty guitars: Gibson SG standard (1977)•Gibson LP custom (1979)
Amps : Mesa Boogie Mark IV•Mesa Nomad 45•Mesa TA-30•Vypyr tube 60+Sanpera I
Other: Effectrode Blackbird•Kingsley Jester•AMT SS11-a•Weehbo JCM Ltd.•Zoom G5•J.Coloccia Big Cannoli

GRE2608
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by GRE2608 » Fri Jul 20, 2012 8:24 am

Hello bgh,

you got it right alright!

The objective of my mod is to offer better (more detailed) volume control. This is in fact the real need for most people and not power control via true attenuation which is co-related to volume only for tube amps. On our case, the power output of a Vypyr is not linearly linked to the Master Volume and following that, (unfortunately) nor is the perceived volume linearly linked to the Master Volume.

About your question, to my understanding, (now that I have better volume control :D) the TransTube logic seems to be placed on the pre-amp stage though some stomps and effects do make it feel like it does relate to volume levels. This would seem to me as the logical decision for a Solid State Amp as you would want the TransTube to offer tube simulation even at very low volumes. At the same time the existence of the Power Sponge pot on bigger models does imply that there is some connection of the TransTube on the power stage. Still, I cannot confirm any of the two at this point so please don't take my comments for granted as it is only my perception from the Vypyrs behavior; it would be helpful if someone from Peavey could clarify this for everyone.

With respect to my original plan for the 75, I was only going to use the Power Sponge pot so we won't have to add an extra pot for the Volume Sponge Mod. The Power Sponge wiring would never be electrically involved in the mod as the two serve different parts of the circuitry. I would just bypass the pot by making a full power connection on its original cables, just in order to free up the pot and use it for our purposes.

Now, the reason I used the term Attenuator is because the mod is simulating the result of what most people would expect from an attenuator; although it is not an actual attenuator. This is the reason why, at the end, I called it the Volume Sponge Mod. As you correctly point out it makes no sense to use an attenuator on a Solid State amp as you don't need to drive hard its power circuitry in order to get it to exhibit distortion.


I want to thank you for your comments.
Hopefully they will help others to understand more about the works of the Volume Sponge Mod.

AvivX
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Re: VYPYR 30 Attenuator - "The Volume Sponge Mod" + PHOTOS

Post by AvivX » Wed Jul 25, 2012 11:59 pm

may i ask why make an attenuator for a SS amp?

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