Clip of my just completed HRM Dumble

[tobykea]

Hi there,

Just finished my Dumble clone last week and thought I'd post a clip of it in use on it's first night.

Appreciate any comments on the Overdrive tone.

It was recorded in a club I play at. Using a Ibanez 335 copy on the neck pickup. There are two guitars( A Strat also) but the Dumble is the second solo.

I still think it needs a bit of tweaking in the ODS department but I think it's a good start.

Cheers,

Toby

[mat]

OOH Hotfingers Very cool solo

What were Your settings on the amp?

[Jeph]

Wow, that was a killer solo. That amp sounded nice, congrats!

[tobykea]

Thanks, Matt and Jeph.

Settings for the amp were as follows, OD drive at about 10 'oclock and Level up about 80%.

HRM tone stack set: Treble around 40%, Bass at 50%, Mids at 40%.

I've got a 12ax7 in the Dumbleator section and I think it has too much gain. I can't turn the Clean channel volume pot up past about 10% without the amp distorting like crazy. There is something strange with the gain distribution I need to sort out.

I might try a 12at7 instead and see if that changes anything.

Cheers,

Toby.

[Normster]

Kinda hard to judge the tone with my jaw on the floor. Smokin' solo!!! All kidding aside, your amp sounds a lot like my HRM, but maybe just a touch darker (which I like). The bottom end sounded great, no mush at all even with the neck pickup. Those can't possibly be stock Ibanez pickups.

[tobykea]

Thanks Normster, appreciate the comments.

Yeah, the pickups are just stock Ibanez.

The guitar itself is quite a dark sounding thing compared to other 335's I've played. I also play a Tele quite regularly and that sounds great with plenty of highs too.

I'm just a bit bothered with this gain distribution problem at the moment. I hav'nt got the scope back into the amp yet to find out which stage is breaking up early but I have a feeling the Dumbleator has something to do with it.

I have the amp setup so that the Dumbleator is always in circuit. I have no means of switching it out which is what I want.

More tweaking to do I suppose.

Cheers,

Toby

[dogears]

Very nice Toby!

So, which schematic did you use a foundation? Some are much more "right" than others.

You should not be having the volume issues you describe unless there is something amiss. All volume pots are audio taper btw.

Excellent playing btw. See you posted over at Play Jazz Guitar too.

I occasionally post there....

[Tonegeek]

Thanks, Matt and Jeph.
I've got a 12ax7 in the Dumbleator section and I think it has too much gain. I can't turn the Clean channel volume pot up past about 10% without the amp distorting like crazy. There is something strange with the gain distribution I need to sort out.

I might try a 12at7 instead and see if that changes anything.

Toby.

I noticed you said you based your build on a schematic you saw in one of my posts. It is basically the ODS_101 schematic but I changed the first plate resistor which may give a bit more gain that I needed, but that you may not need. I would put that back to 220K just in case it is causing an issue. The rest of the schematic is pretty much ODS_101 except I think I also used a 5uF cap on OD2 instead of the recommended 1uF. I also think the presence circuit on ODS_101 is different than what I used. I tried them both and did not care for the ODS_101 version. Not sure what is Dumble "correct" on the presence. They may both be right depending on the decade.

A 12AT7 or 12AU7 (for even less gain) might help. You may have to play with the supply voltage as these tubes seem to draw more current than a 12ax7. Try leaving out your FX unit for the moment. This may help determine if your FX unit is being overloaded. If the sound is different with the FX out you will get some ideas about what to do next. I can only turn my send up to about 25% before my FX (which fortunately has a meter on it) begins to overload. The return on mine is usually about 40% which doesnt mean much as the FX unit also has level controls. The D'lator complicates getting the proper gains structure as the send and return pots can be considered master volumes. I find that it takes a bit of extra tweaking to get the amp the way I want it, but it is worth the effort because it also makes the amp more versatile. You can fatten up or brigthen up the sound just by fooling with the gain structure.

[tobykea]

Thanks for the feedback Dogears and Tonegeek, appreciate it very much.

The schematic I have used is the ODS-101 and another schematic which is very similiar. I basicallyy downloaded about 5 different versions of the schematic which were all available here and went with the configuration most people seem to be using.

The plate resistor I have for the first stage is 220k and I have the usual cathode bypass caps in the ODS stages, 5uF and 1uF.

I'm about to go home from work and get stuck into the amp again with the scope so I should find out where my gain issues are.

The effect unit I am using for my reverb is a Line 6 Pod XT which expects to see a guitar at it's input and probably not the levels at which the signal is coming out of the send jack. That would explain why I can't turn the pot up very much. Like you say Tonegeek, the distortion is probably coming from the effect unit.

Anyway, thanks for all the help and advice. I'll post back again when I make some progress.

Cheers,

Toby

[John747]

I really enjoyed that. Any chance of pictures?

[hipbluescat]

Hello

I compliment you on the tone and playing.

The tone was great and the clip was good enough for my taste that I listened to it many times because it was that good.

Is the Dumbleator a separate to the amp and what is its function ?

What FX unit are you using ?

Would love some pictutres if it is not to much to ask.

Regards