D'lite 6L6 build: Bright!

[lbradshaw]

Hello, All. I have been reading this forum for sometime now. I love it!

Anyhow, I finial got around to doing an "D" style build. It's mostly an D'lite with tweaked values, non-HRM, running 6L6s. It sounds pretty good, but the whole amp just seems way too bright. I have tried at Strat with single coils and also a guitar with Humbuckers, either way it's pretty darn bright. An when you flip the bright switch ON it becomes almost deadly bright! What are the best places to tweak for this style of amp? I thought about increasing the first 330p cap. Also, I do I need an treble bleed some place? Thoughts?

[Structo]

I am kind of in the same boat.

I had changed a lot of values and the last mod I did was the OD network mod with the .05uf cap coming off of the OD trimmer.
That seemed to make it too bright so now I have to adjust other things.

What is the value of your bright cap?

If you have a 270pf, you may want to try a 120pf.

Also change your treble cap to 330pf.

Usually people complain that the D'Lite is too bass heavy in it's stock form.

Have you seen the Tweeked layout?

I have most if not all of the changes in my amp.

How does your presence control work for you?

You might want to change that to the Dumble style.
That is with the resistor coming off the left lug to ground and the 1uf cap going from the wiper to ground and the first lug left open.

Also, do you have the right two lugs on the bass pot jumpered?

These should apparently be jumpered then unjumpered when the PAB relay is on. If you have relays that is.
If you don't have relays you may want to try it jumpered.
If you have any test leads with alligator clips you can try jumpering it when you are playing to see if you like it.


The treble bleed mod is also shown here.
You should use a pot or trimmer in the 500K range in series with the .001uf cap to find the approprate value, or just try the 150K fixed value.

[bluesfendermanblues]

Hello, All. I have been reading this forum for sometime now. I love it!

Anyhow, I finial got around to doing an "D" style build. It's mostly an D'lite with tweaked values, non-HRM, running 6L6s. It sounds pretty good, but the whole amp just seems way too bright. I have tried at Strat with single coils and also a guitar with Humbuckers, either way it's pretty darn bright. An when you flip the bright switch ON it becomes almost deadly bright! What are the best places to tweak for this style of amp? I thought about increasing the first 330p cap. Also, I do I need an treble bleed some place? Thoughts?

Best advise on my behalf is: Give it a month of intense playin to burn in the amp. New components are bright and hard sounding. You'll be surprised by the change in sound after a month. Don't start tweaking before the amp is burned in.

[Deric]

What kind of speaker are you using?

[lbradshaw]

I am kind of in the same boat.

I had changed a lot of values and the last mod I did was the OD network mod with the .05uf cap coming off of the OD trimmer.
That seemed to make it too bright so now I have to adjust other things.

What is the value of your bright cap?

If you have a 270pf, you may want to try a 120pf.

Also change your treble cap to 330pf.

I checked I do have all those tweaks in place.

Usually people complain that the D'Lite is too bass heavy in it's stock form.

Wow, I wonder if that is an 6V6 vs 6L6 thing.

My presence is not "right" with the world right now. I am using the wrong value pot. But, I find that for the bright issue, right now, turning it all the way down is better. I will have to look into this more when I get the right pot.

Also, do you have the right two lugs on the bass pot jumpered?

Nope, I don't. I assume you mean the right two pots looking from the back of the pot?

Deric: I am using an G12H

I hope this amp does in fact get a little less bright over time.

There is one other problem. The OD channel is pretty buzzy. It does not have the smooth overdrive I was expecting. I have played with the OD trim pot. That really does not seem to make much difference(in relation to the buzzy OD)

Also, here are my current voltages:

Plates
V1a 199v
V1b 202v
V2a 206v
V2b 213v
V3a 299v
V3b 297v

V4&V5 454v

[Deric]

What are your snubbers on V2? If they are 270p try 330p.

Definately try connecting the Bass pot wiper to the right hand lug (looking at the back of the pots from inside the amp).

I also agree with the notion that the amp will change/warm up over time.

[lbradshaw]

What are your snubbers on V2? If they are 270p try 330p.

Definately try connecting the Bass pot wiper to the right hand lug (looking at the back of the pots from inside the amp).

I also agree with the notion that the amp will change/warm up over time.

The Snubbers are indeed 270p. I might give 330p a go.

I'll try the bass pot change.

Thanks for the ideas, you guys.

[brownnote]

How about some pics?

Shielded wire in the OD and a treble bleed will smooth out the OD some

You might try a 100K slope resistor along with the other suggestions.

[Structo]

Is this a kit build or scratch build?

I messed around with mine today.

I jumpered the bass pot to the PAB relay so when PAB is on the jumper is disconnected.

I haven't tried a lower slope resistor yet.
What's that do for ya?

I messed around with the treble bleed/ OD Smoother some today.

I have a resistance decade box and I put that where the resistor goes to the ground buss.

It sure is a subtle effect.

I had a fixed 150K resistor so when I had the decade box connected I cranked the knob all the way down to 6.8K and way up to 1 meg.

It seemed the lower value resistor had more effect in taking the top off the tone but it is very subtle, it doesn't jump out at ya.

I was going to change the 180K resistor on OD2 to 150K but I couldn't find one in my parts drawer.

I also still haven't installed the choke yet either. I looked at it today and it will require major surgery because I will have to lift the power supply filter board to fasten the choke down....

[Bob-I]

The first question, is this with clean as well as OD mode, or just one or the other?

If it's both, then I'd look at the tone stack and PI. If it's just OD then look at a treble bleed, snubbers and some tweaks to the series resistors.

[lbradshaw]

This is a scratch build. I would send some pictures but it's currently in a test chassis, so it looks like crap. I did try to do the lead dress half way decent, but it's not near what a final build would be. This could add to some of my problems, which is fine. Any issues that can't be workout in the test phase, I'll fix in the final build(cross fingers).

I did jumper the Bass pot wiper and right lug together, and I like the results. It adds bass, but also seems to thicken up the whole amp. I would not mind having this on some kind of switch. Which begs the question: Which would be better this bass Pot mod, or an mid boost? And what is the reason for disconnecting the bass jumper when the PAB, via relay, is turn on?

As far as the buzz, slight harshness sound, it is only the OD. I do already have a shielded wire on the OD. Brownnote, you say in the OD, do you mean other then to and from the OD pots?

When you guys talk about adding a treble bleed to smooth out the OD some, do you mean like that image above that Structo posted, "DLtreble_bleed"? which is basically an cap and resistor from the right lug of the OD Level to ground?

What will the 100K slope resistor do for me?

I do have an choke kicking around here some place that I am planning on trying. But, I don't know how long after adding the choke that I will be able to still call it a d'lite.

[Structo]

When the PAB is switched on it simply removes the bass and treble pot from the circuit.

If the bass pot it jumpered this will leave the bass pot connected.
So you take a wire from the input and wiper of the bass pot and connect it to the normally closed switch on the PAB relay.

The PAB is a funky circuit in a way because if you have the bass and treble turned up quite a ways the difference when you turn on the PAB isn't as great of a boost would be if the bass and treble are turned down and PAB is switched on.


There should be four shielded cables from the drive and level pots to the board.

Scott recommended not to use shielded cable on the master.

Another thing that will affect the overall tone is what kind of shielded cable you use.

If it is a cheaper type with higher capacitance it will act as a high cut filter and make the tone less bright.

If you use high quality cable with low capacitance, it could make the amp brighter.

Most these guys have suggested using a middle of the road cable for this.

The treble bleed as I mentioned is a pretty subtle effect.

If I were you I would take a 500K trimmer and wire that as a variable resistor in series with the .001uf cap from the input of the drive pot to the buss wire with the cap on the pot and the trimmer to the buss wire.

Right now I have mine turned down to around 45K.

I'm not sure about the slope resistor as I haven't changed mine yet.

[Bob-I]

As far as the buzz, slight harshness sound, it is only the OD. I do already have a shielded wire on the OD. Brownnote, you say in the OD, do you mean other then to and from the OD pots?

No, that's the correct place for shielded. What value are the snubber caps on V2, plate to cathode? I think the schem shows 270pF but on some builds I've increased these to 330 and even 390pF.

What will the 100K slope resistor do for me?

It shifts all the tone controls to a lower frequency. If the clean tone is to your liking, this isn't the fix as it'll change both clean and OD.

[Normster]

IMHO, a bright amp is a nice problem to have. It's much easier to tame a bright amp than it is to brighten up a dark one. If you're OK with the clean tone, then I think the suggestions for a treble bleed are in order. If you need to tame the clean tone as well, reduce (or eliminate) the bright cap from the master. Other places to tweak are the treble pot itself. For a dark amp, I use 250kB. For brighter amps, use a 250kA. Alpha pots are 15% taper while CTS are 10% so you've got some choices there as well.

If the amp is really missing bass content rather than just too trebly, try increasing the size of the coupling caps or cathode bypass caps. As Moss said, you can also decrease the size of the slope resistor to increase mid/bass response.

Lastly, I recall Brandon having a problem with an overly bright amp that turned out to be the brand of PS capacitors. Apparently Nichicon is not nearly as smooth and warm as F&T, Sprague, or Xicon.

[lbradshaw]

There should be four shielded cables from the drive and level pots to the board.

Scott recommended not to use shielded cable on the master. .............

Good info. thanks.

If I were you I would take a 500K trimmer and wire that as a variable resistor in series with the .001uf cap from the input of the drive pot to the buss wire with the cap on the pot and the trimmer to the buss wire

If you're OK with the clean tone, then I think the suggestions for a treble bleed are in order.

I am thinking about trying a treble bleed of some type. This goes Post OD vs Pre OD?

Other places to tweak are the treble pot itself. For a dark amp, I use 250kB. For brighter amps, use a 250kA.

The type of taper will make a difference in Brightness of the amp? I did not know this... you learn something new everyday.

No, that's the correct place for shielded. What value are the snubber caps on V2, plate to cathode? I think the schem shows 270pF but on some builds I've increased these to 330 and even 390pF.

V2 does have 270Ps on it now. I'm thinking of changing them.

Thanks for all your suggestions. I will put them all on my list of things to try.