Loving my Diavlo RD20H, questions on V1-V4 location & tubes?

Hey Folks, hi, first post. Been lurking a while. I've recently got back into playing guitar after about a 10 year hiatus, got a new rig!, have some questions that I can't seem to find answers to searching around. Put myself through college teaching guitar and then playing fell by the wayside when I entered the "real job" world. I'm really excited to be getting back into it.

I spent a month or so reading & listening to clips on YouTube, plus playing whatever they had in local music stores, tried to find a new rig that was killer sounding & in my budget. My favorite thing at the local music shop (not many options mind you) was the Blackstar HT-5 head with the matching 1x12 cab. I didn't think it was perfect but it was pretty good. I actually liked the HT-20 combo sound better but there just wasn't enough gain for me. So, I ended up buying a HT Metal 5 head & a Randall Diavlo 1x12 ported cab with the Vintage 30 speaker. Well, it sounded like crap. There was a nasally mid presence that just would not go away. In hindsight the HT-5 should probably be run with its native speaker, or maybe a G12T-75 but definitely not a V30. With the V30 I could literally only get one good tone out of the setup, that was high gain scooped running on my EMG 81 bridge pickup. Not to mention it just didn't have the balls to light the V30 up. So, I returned it. I will say that the HT-5 did have really great reverb.

Good thing I did. I replaced it with a Randall Diavlo RD20 head that I like much, much better. It was at the top of my head budget & I really wanted an all tube high gain metal sounding head with 2 channels. I'm a little bummed it doesn't have reverb but oh well. It has surprisingly nice cleans and a really nice crunch- plus plenty of headroom for what I'm doing which is playing for fun & relaxation. Whatever Fortin is doing over there it seems to be working well. It does however go a little flat if I run it really hard so I'm looking at trying some better tubes in it, plus when I crank it the microphonics are terrible. This unit came with (2) Ruby 6V6GTSTR power tubes & (4) Ruby 12AX7AC5 (Shuguang 12AX7 9th gen?) pre-amp tubes.

First off, can anyone confirm which positions are which V position? Here's my assumption from general theory but I can't find any Diavlo diagrams.

Back of head
......V4(PI)...6V6...6V6
.......V1......V2.......V3
Input jack

I'm pretty sure I want to try a Tung-Sol in V1 and a Mullard in the PI. Still looking for thoughts on Tung-Sol vs. other in V2 & V3. I would like to know what the jobs are for V1-V2-V3, that might help determine what tubes would be good choices for each. Can anyone tell me what each tube is responsible for?

I'm also considering either a Tung-Sol or a JJ 6V6 in the power section. I've read all about how TS is better quality & smoother, but the JJ are punchier & sound more like a 6L6 but with mixed reviews on reliability. I know the real answer is to try them all but I'm hoping to make some educated guesses so I don't waste precious cash! If anyone has thoughts for me I'd appreciate it.

In addition right in front of each 6V6 there is a dashpot screw adjustment that I assume is for biasing the power tubes, but I can't find any information on a procedure for biasing a RD20H or a RD45H (same design). I asked Randall tech support but I didn't get a response. Not only do I live in a rural area but I prefer to work on my own stuff rather than paying someone to do it for me, if I could do it myself. I'm sure you know the feeling.

Anyway thanks in advance, seems like a great forum for answers. Long term I'm looking to get another matching Diavlo 1x12 cabinet & load it with a G12T-75 to fill out the sound. I think the Diavlo series is a really great setup for the money.

I have a RD45

V1 and V2 are for OD
V3 for cleans
V4 PI

Tung sol and LPS often recommended in V1 and V4

bias : you have to adjust it, then return the chassis, take tension at the 1 ohms resistances. if it's not good, then readjust, re turn the chassis....little annoying to do, but it can be done.

plate voltage on RD45 is 440 volts. I biased mine around 40mA

How sound the 1X12 ported randall cab with the V30 and the head in details ? it is also front loaded....

Thanks Nico. The V30 I think sounds great with the RD20 head. Yes, that cab is front loaded with a closed back & front ports. I'm getting great clean tones from my EMG 85 neck pickup, and great chugga chugga gain tones from my EMG 81 bridge pickup. The cleans probably don't have the headroom for gigging (at least without breaking up) but the gain channel gets earplugs-to-be-in-the-room loud. If I pump up the mids and roll back the bass on the 85 I can get an OK dirty British sound too. I haven't really had the chance to play any high dollar heads but this thing gives you loads more tone variability than the Blackstar, and for metal I think it's probably better than anything else in the price range.

GJgo":1wwi116p said:

Hey Folks, hi, first post. Been lurking a while. I've recently got back into playing guitar after about a 10 year hiatus, got a new rig!, have some questions that I can't seem to find answers to searching around. Put myself through college teaching guitar and then playing fell by the wayside when I entered the "real job" world. I'm really excited to be getting back into it.

Good thing I did. I replaced it with a Randall Diavlo RD20 head that I like much, much better. It was at the top of my head budget & I really wanted an all tube high gain metal sounding head with 2 channels. I'm a little bummed it doesn't have reverb but oh well. It has surprisingly nice cleans and a really nice crunch- plus plenty of headroom for what I'm doing which is playing for fun & relaxation. Whatever Fortin is doing over there it seems to be working well. It does however go a little flat if I run it really hard so I'm looking at trying some better tubes in it, plus when I crank it the microphonics are terrible. This unit came with (2) Ruby 6V6GTSTR power tubes & (4) Ruby 12AX7AC5 (Shuguang 12AX7 9th gen?) pre-amp tubes.


Anyway thanks in advance, seems like a great forum for answers. Long term I'm looking to get another matching Diavlo 1x12 cabinet & load it with a G12T-75 to fill out the sound. I think the Diavlo series is a really great setup for the money.

Click to expand...

I have an RD45.
The stock Ruby tubes are JUNK.
Every freaking Ruby pre tube I've had has awful quality pins.
They feel like they are made of lead cause they bend way too freaking easy.

My RD45 didn't sound at all like a high gain metal amp when I first got it and played it.
I boxed it up.
Then I heard more video's and one posted on this forum and decided to unbox it and retube it.
2 of the 4 Ruby pre tubes has seriously BENT pins that were not in any slot.
That explains the lack of gain.

I put in a Tung Sol in V1 and JJ's high gain in V2, V3, and V4.
NOW it sounded like it should.
Quite nice and worthy of being a high gain Metal amp.
It's best with the boost on.

Also, I took out the Ruby power tubes as it sounded like the amp was too hotly biased as it felt kind wooden.
I put in a spare set of Ruby 6L6's that were a very different rating and it sounded better, spongier, better feel and tone.

I too ran it with a pair of V30's and that is a great combo.

In the end I have decided to return the RD45 and stick with my Egnater Vengeance.
The RD's are really nice and the size is excellent.
The lack of reverb is an oversight, but I got a TC Electronics Hall of Fame reverb pedal, the red one, and it's fantastic with this amp.
Look on Amazon or Ebay and you can find the Hall of fame reverb for like $110 shipped.

My Vengeance head has more gain and a smoother saturation and more versatile EQ, that's why it won over the RD.
But, the price difference is double.
Plus, I almost never run the Vengeance in full 120 watt mode. I run it at 60 watt half power mode, which compares to the RD45's 45 watts.

Great amp you've got.
Find the right tube and it'll growl and scream.
Put a nice clean boost in front and it's even sweeter.
If you run an external boost you can dial back the amps gain a bit, which will clean up and tighten up the tone yet still have more gain.
Enjoy!

Does anyone know if one of the V positions in this head is a cathode follower? I've read you shouldn't use Tung-Sols and some others in this position.

no cf in rd45
4 stages plate driven tone stack OD
2 stages for clean

Cool thanks. Anyone else have feedback on different 12AX7 tubes they've tried in their Diavlo? I have some folks recommending Tung-Sol all the way, others saying TS in V1 and this or that in the other positions. I've also heard Mullard in the PI. I'll probably try different options eventually but I'd like to buy some not-Rubies as a starting point.

I had 2 RD45's. JJ 6L6's really make it monster. I ran a Tungsol V1 and JJ's V2 & 3, and an LPS in the PI. Sounded phenomenal. I might get a 3rd.

Just curious... Why have you sold it twice?

I really went back & forth between the 20 & the 45 since it's only a hundred bucks, came down to I just don't need that much volume for jamming. The 5W would have worked for me but it was a no-go since it only had one channel. I only wish I could have heard them back to back first in case the tone difference between the 6V6 & the 6L6 would have changed my mind.

Does anyone know if the speaker emulator output can be used for headphones?

So I've noticed that when playing at the lowest possible volume (kids in bed) that after it's been on for a while, the volume will slowly start to oscillate from where I had it set down to almost off. It does it concurrently on both channels. I need to try it during the day with more volume but.. Is this normal at minimum volumes or a possible tube issue?

GJgo":3ti7dvkj said:

So I've noticed that when playing at the lowest possible volume (kids in bed) that after it's been on for a while, the volume will slowly start to oscillate from where I had it set down to almost off. It does it concurrently on both channels. I need to try it during the day with more volume but.. Is this normal at minimum volumes or a possible tube issue?

Click to expand...

My Orange Dark Terror did the same thing. Traded it off...

The rd100 and rd45 have done this with me as well. Im not 100% sure if it was the amp itself or a certain tube I had in there. I think I tried the same tube in both.

Ok so I put together a short half-ass tone comparo vid between the HT Metal 5 & the Diavlo RD20. I think the Diavlo is light years better, can't wait to roll some tubes in it.

http://youtu.be/q9ZcyzMoztY

Good choice on ditching the blackstar. It sounded like garbage.

So I picked up a JJ 12AX7 locally, and ordered some Tung-Sols & a Mullard 12AX7 to roll. (Local stores only had JJ & Electro-Harmonix.) I went ahead & ran the JJ through the slots today- here were some initial thoughts.
- In the V1 & V2 OD slots the Rubies had more gain, but the JJ had a little more bite (but less gain). The Rubies also go flat when I crank it way up.
- In the V3 clean slot I like the JJ better- but not because of the tone. The tones were equitable. The Ruby tube broke up way too early for a clean channel, where the JJ had quite a bit of clean headroom. I could still get it to break up at the top of the gain knob but there was a lot of real-estate in-between. The Ruby was just a lot less useful because it broke up so early that I had to roll back the volume knob on the guitar to get any clean volume out of it, and that kind of dulls it down.
- In the V4 PI slot I can't say I could really tell a difference.

More to come. I've been playing around with Garage Band on my iPhone, the mic is acceptable but I really need to get a XLR input so I can use the emulated out!

I've got some more tube rolling thoughts to share now, the good I ordered from Doug's came in.

V1:
The Ruby was kind of flat.
The JJ had some bite, until it crapped out- which didn't take long. Less gain than the others.
Mullard- this one had an awesome clean sound to it, loved it. The gain was a little meh though.
Tung-Sol, this is the best of it all. Great gain, great tone. The cleans weren't as nice as the Mullard but this isn't a clean amp. Winner!

V2:
The Ruby had high gain, but it was flat & toneless.
The Mullard was nothing special.
The Tung-Sol was once again the winner. Not quite as much gain as the Ruby, but it has great tone and still sounds good when pushed. There's an edge to the TS sound that kind of grows on you.

V3:
The Ruby breaks up too soon.
The Mullard wasn't anything super special here, definitely not the awesome clean tone that it gave in V1. It was about the same as the TS- which was still good, but not epic.
The Tung-Sol had a good tone here, but not killer. I still left it in as it was the best of the bunch.

V4:
I'm not sure I could really tell much of a difference. I ended up putting the Mullard here because they are pretty neutral & make a good choice for the PI, where perhaps the TS isn't as good of a choice? What I've read, anyway.

It's pretty clear that I'm not a fan of the Ruby anywhere. Lots of better choices. Before the JJ crapped out I could tell that it was a different sound than all the others, more of a bite to it. I can see how some would like it but it wasn't my thing. Now I'm looking forward to trying something else in the power amp. Probably a Tung-Sol 6V6, maybe a JJ..?

GJgo":32s7c59k said:

I've got some more tube rolling thoughts to share now, the good I ordered from Doug's came in.

V1:
The Ruby was kind of flat.
The JJ had some bite, until it crapped out- which didn't take long. Less gain than the others.
Mullard- this one had an awesome clean sound to it, loved it. The gain was a little meh though.
Tung-Sol, this is the best of it all. Great gain, great tone. The cleans weren't as nice as the Mullard but this isn't a clean amp. Winner!

V2:
The Ruby had high gain, but it was flat & toneless.
The Mullard was nothing special.
The Tung-Sol was once again the winner. Not quite as much gain as the Ruby, but it has great tone and still sounds good when pushed. There's an edge to the TS sound that kind of grows on you.

V3:
The Ruby breaks up too soon.
The Mullard wasn't anything super special here, definitely not the awesome clean tone that it gave in V1. It was about the same as the TS- which was still good, but not epic.
The Tung-Sol had a good tone here, but not killer. I still left it in as it was the best of the bunch.

V4:
I'm not sure I could really tell much of a difference. I ended up putting the Mullard here because they are pretty neutral & make a good choice for the PI, where perhaps the TS isn't as good of a choice? What I've read, anyway.

It's pretty clear that I'm not a fan of the Ruby anywhere. Lots of better choices. Before the JJ crapped out I could tell that it was a different sound than all the others, more of a bite to it. I can see how some would like it but it wasn't my thing. Now I'm looking forward to trying something else in the power amp. Probably a Tung-Sol 6V6, maybe a JJ..?

Click to expand...

It's fun swapping tubes ain't it.

I prefer the Tung's over the JJ's too.
The JJ's are a pretty good tube though. Sounds like you got a bad one.
The Mullard has some good tone, as you experienced it's not a very "hot" tube.
Get a couple of Sovtek LPS. I really like this tube in the PI position, really nice.
Use the other one in any of the pre stages to try it out.

In my Vengeance I've got an LPS in the high gain section of the clean channel, and in the PI.
Sounds great.

I want to try some Gold Lions next.
There are 2 versions, a Chinese made tube that's lower in cost but gets great reviews, and a premium gold pin version made in Russia that costs a good bit more than the non gold pin version.
I've found them at $27 and $44 each, but I'm looking for a lower cost source.

So I did a little more swapping around after playing this set for a while.

V1 Tung Sol
V2 gain Tung Sol
V3 clean Tung Sol
V4 PI Mullard

The fizziness from the Rubies is gone, which is good. There was also a much more pronounced midrange from the Tung Sols that had its own flavor. However, when I started to crank it there was a bit of harshness that caused ear fatigue pretty quickly in both the clean & the gain channel- too bright? In an effort to take some of the harshness out all over I tried this next. I do like the tone of the Tung Sols for high gain, but I think having them in 1-2-3 may have been too much of a good thing.

V1 Mullard
V2 gain Tung Sol
V3 clean Tung Sol
V4 PI Ruby

That definitely helped with the harshness on both channels, it did darken it a touch. Also the cleans picked up some fatness & the gains were still plenty heavy. Overall it sounds pretty good, except I’d like to see some more definition in the note separation when playing heavy chugga stuff- it was a little muddy. So, next I tried this combo.

V1 Mullard
V2 gain Tung Sol
V3 clean Tung Sol
V4 PI Tung Sol

This may be the best combo yet- not perfect, but pretty darn good. The gains from the Mullard in this configuration is still plenty heavy. A little of the Tung Sol middy-ness is back but without the ear fatigue, and the note separation seems better. So I’d like to try maybe 1 or 2 other tubes to continue the development just to make sure I'm not missing something. What to try next? A LPS in the PI and..? Does the description of “wanting more note separation” make sense?