#1
OK, I got my HRD 410 recently and it had a few qualities that I wasn't happy with. One, the volume and master knob cause a huge jump in volume between 1 and 2, and then it seems to level out from there. Two, I wanted to reduce the power output and clean headroom so that I can get some saturation/distortion at more reasonable volumes.

I did some searching and the root of the first problem is that Fender uses linear pots for their volume knobs (at least on this amp). This causes volume to increase logarithmically as the knob is turned up. The fix is to switch out the linear pots with audio (logarithmic) pots. This allows the volume and master knobs to increase volume linearly, and with no sudden bursts of volume with just a small adjustment of the knob. I ordered two of these Fender audio pots from here, and they are a special type that will directly drop in and replace the originals.

http://www.tubesandmore.com/

http://www.tubesandmore.com/new/scripts/silverware.exe/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=R-VHD-250KA

I ordered two, and have a few pics from when I installed them:

The amp circuitry exposed, and the main board folded out to expose the solder side of the board:


The original linear pot after being desoldered:


The new audio pot ready to be installed. You can see that the new pot is pretty much identical in appearance to the old ones. The new ones snapped right into the holes on the circuit board without any trouble:


The new volume pot for the clean channel installed. Soldering this thing in was very easy:


The new master volume pot (for the drive channel) installed:


Everything fired back up just as it should, and the fix worked as expected. Now, the volume at around 5 is the same as it used to be at 2. This makes it much easier to tweak at practice levels. Both the drive channel and the clean now have the audio pots controlling volume.

Now for the second mod. I found a site with some Hot Rod series mods, and saw a good idea for swapping out the power tubes and reducing the power, while making the amp a little more suited for rock.

http://studentweb.eku.edu/justin_holton/tooloud.html#EL84

I found the parts at MF, and it's not a cheap mod but is well worth it in my opinion.

http://www.musiciansfriend.com/product/THD-YJSD-Yellow-Jacket-Standard-Duet?sku=210390

The adapters come in a pair with JJ EL84s. The swap is easy, just pop in the adapters and then plug the EL84s into the adapters. The adapters have a built-in bias circuit, so no other work is needed.

I have a pic of the Yellow Jackets installed:



Overall, I'm really happy with the amp now. I can get some real distortion out of the amp without a pedal, and I can use a distortion or overdrive pedal to get a good rock sound without having to turn the volume up to deadly levels.
-Schecter C-1 Artist Limited Edition Left-Handed
-Fender Hot Rod Deville 410
-New York Pro Acoustic

Quote by Random emo kid
I'm so emo even my tears cry.

Quote by wahappen
I'd probably give my right arm to be ambidextrous.
#3
This is exactly what I need! My amp is so sensitive that slight touches get the parents yelling at me. I'm VERY interested in this! About how easy is this?
My Gear:
Fender Japan Strat (80s)
Gibson SG Standard
Epi Goth Explorer (FAV)
Fender HotRod DeVille
Ibanez TS-9
Akai Wah Pedal
Quote by SHANANDO

Seriously, this sounds like a pussy squable from Saved By The Bell or some **** like that.

Last edited by Mui at Jul 14, 2006,
#4
The hardest part was just getting the solder side of the circuit board exposed. You have to remove all the knobs on the amp, then remove the nuts/washers on each control and input jack. This will allow the controls to be pulled out from behind (Where they are mounted on the circuit board). It's a tight squeeze trying to pull the circuit board back and flipping it out in order to get to the solder side, but anyone with patience should be able to do it. After that you just need some solder, a soldering iron, and some desoldering braid (looks like a little rope of braided copper). Desolder the old pot (short for potentiometer, it's what the knobs turn), then swap it with the new one and solder in the new one. It doesn't seem hard to me, but it might seem very difficult to someone else, so you might want to find a friend who knows a little about soldering/electronics.
-Schecter C-1 Artist Limited Edition Left-Handed
-Fender Hot Rod Deville 410
-New York Pro Acoustic

Quote by Random emo kid
I'm so emo even my tears cry.

Quote by wahappen
I'd probably give my right arm to be ambidextrous.
#5
Mmmm, I got to load a big, nice Hot Rod Deville, 65 Twin and a Vibro-verb (i think) onto a stage today. God, I love summer festivals
Will says:
DON'T FEAR THE REAPER!
- SmarterChild - says:
I don't know if I can help it.

Member #6 of the "I play my guitar as high as Tom Morello does" club
#6
You can build a "Yellow Jacket" for no more than 10 bucks each...
Nice job with the volume knobs, my home built amp has a linear volume(no master volume) and it does have its quirks, but I kind of like it, dunno why.

I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#7
Quote by That_Pink_Queen
You can build a "Yellow Jacket" for no more than 10 bucks each...
Nice job with the volume knobs, my home built amp has a linear volume(no master volume) and it does have its quirks, but I kind of like it, dunno why.



I'd like more info on how to build one
-Schecter C-1 Artist Limited Edition Left-Handed
-Fender Hot Rod Deville 410
-New York Pro Acoustic

Quote by Random emo kid
I'm so emo even my tears cry.

Quote by wahappen
I'd probably give my right arm to be ambidextrous.
#10
by doing that you don't lose some volume? saying you have a gig and need that volume..
Gear:

Ibanez SoundGear SR300DX Bass

Digitech BP200
#11
You dont loose volume. Its the same amount of volume. It just changes how the volume increases. Heres a diagram to explain:


Linear pot- red
Audio/Log pot- yellow
#12
OMG thats great then
Gear:

Ibanez SoundGear SR300DX Bass

Digitech BP200
#13
What a great way to get a handle of electronic modding. How could you describe the change in distortion? Have you cranked this amp to bare balls yet after the mod to see how it sounds?
~Bryan~
~~One Off Custom Strat~~
- 3 piece alder body
- Maple on rosewood 21 fret neck
- '82 Fender pickups


~~'92 Toyota Supra~~

- 1JZ-GTE (TT, front mount intercooler, 15~psi)
- Tuned on 93 octane
- HKS 3" exhaust
#15
Very nice modding! And great ideas on what to do for it.

You could have added sound clips from before and after though!
"Breathe, breathe in the air
Don't be afraid to care"

Fender Strat/Tokai LS80>few pedals>Orange Rocker 30
#16
Quote by dropin_biking
What a great way to get a handle of electronic modding. How could you describe the change in distortion? Have you cranked this amp to bare balls yet after the mod to see how it sounds?
~Bryan~


The pots don't change the distortion, but the tube change definitely gave the amp a much better rock distortion. Before, it had a loose and farty sounding distortion (at least at the volumes where my ears wouldn't bleed). Now it has a much tighter distortion. If I turn the mids way down then it sounds great with power chords. Now I can get a good lead overdrive in the clean channel without having to crank up to painful volumes also.
-Schecter C-1 Artist Limited Edition Left-Handed
-Fender Hot Rod Deville 410
-New York Pro Acoustic

Quote by Random emo kid
I'm so emo even my tears cry.

Quote by wahappen
I'd probably give my right arm to be ambidextrous.