Changing knobs on a Heartbreaker head. Has anyone done this?

[azernebur]

Hi all,
My first post here. I just picked up a Heartbreaker head in a trade deal on craigslist - green tolex with wheat grill, along with a cream Mk III 2 12 cab with the original Celestion/EV combo. I LOVE the amp and will be picking up a Flux-Drive and Throttle Box to run in front and use my TC Nova System in the loop for Line effects.
Anyway, it's kinda hard for me to see my settings with the black knobs against the black panel, so I want to swap the knobs for some cream chicken heads. I'm having a heckuva time trying to find D shaft knobs. I tried eBay and on-line parts stores, but all I find are straight or knurled shaft push-on or set screw. Has anyone changed their knobs out? And if so, where did you get them?
Thanks so much!

 

[azernebur]

Found my answer! Called up Mesa and spoke with Michael who pulled out an old Heartbreaker he had there and told me what to do. Excellent customer service I must say!

 

[MrMarkIII]

Found my answer! Called up Mesa and spoke with Michael who pulled out an old Heartbreaker he had there and told me what to do. Excellent customer service I must say!

... And that would be... ?

 

[Tommy_G]

There was a really cool looking HB on yakaz a few months ago with each chicken head a different color. NICE.

Congrats on your HB, I have one too, my favorite Mesa! In case you haven't read the multitude of posts on the subject, HB's sound best with 6v6's or EL34's.

 

[azernebur]

Forgot to post what Michael said, sorry. He said a 1/4" set screw knob with the solid brass insert will work perfectly. Now I'm thinking of getting cream Fender knobs used on the old blonde Bassman heads; that might look sweet.

So, here's how I scored this HB, and this is the truth! I had a 2001 MIM Fender Deluxe Super Strat I'd been wanting to trade off for months, but no solid bites on straight trades. I put an ad up in CL selling my Strat for $500 or trade for a Boogie combo. This guy contacts me and offers the HB head AND a Mk III 212 vertical cab in cream tolex, or two Seymour Duncan convertible combos.......straight across for my Strat!!! He sends me pics and I'm thinking this is too good to be true.

So we hook up at his place; nice big house on the hill. Turns out he's a rich attorney with gear up the ying yang. He picked up the Mesa gear at a pawn shop and probably didn't play it at all, considering how much dust was on the head and cab. He played my Strat for about two minutes, I played the HB for a few, 'cause I wasn't really familiar with it but knew it was special just from the immediate tone coming out of it. So he says, 'Do you want to do the trade?' And what do you think I say? I load up the Mesa gear in my car in shock at the score I just made.

Taking the amp to my friend Carl to give it the once over. I'll most likely end up running it with EL34s for that British sound.

I have a cream Mk III purple stripe that will love sitting atop the cab I scored. I personally love the HB better because of it's versatility and blank canvas for tone creation. I am getting some sweet tones outta this thing; here's a quickly sample I made - http://youtu.be/RhlPyljQMX0

Thanks for the replies, guys!

 

[Tommy_G]

If you're going to brit-icize the amp with some EL34's (good choice)....make sure you get some scumbacks in your budget... M75, BM75 and/or Scumnico....all awesome with this amp, and even better with mixed speakers.

i should also note that after some time with this amp, even though it takes pedals better than most amps, that the built in tube tones are so great that I'm just plugging straight in. I had a tech revamp the capacitors in my guitar circuitry to match up with the amp - highly recommended! There's a guy on your youtube vid suggesting the same thing, that's why I brought it up...

I'm officially 'old school' now.

 

[azernebur]

Thanks, Tommy G. Yeah, I love the Mark I lead tone and the clean Love tone; wish I could switch between those two modes - those seem the most useful for me right out the gate. Gonna take me a while to figure this amp out and get to know the tricks and quirks, etc. Gotta learn more about those Sumbacks; I'm a old school Celestion / EV guy myself.

 

[Analog Kid]

Just this week I pulled the 34's out of my heartbreaker to try 6v6's with the bias set in the EL-34 position, like Tommy G suggested.

 

[azernebur]

Just this week I pulled the 34's out of my heartbreaker to try 6v6's with the bias set in the EL-34 position, like Tommy G suggested.

6V6s with the bias set for EL34s; never heard or knew that could be done. What does that do for tone? In reading the manual, that would bring it down to 40watts, which can be done with 2 EL34s on the outside or 2 6V6s on the inside. Curious.

 

[Tommy_G]

I usually have 6v6's in the outside pair, and EL34's on the inside pair. So when I'm at home on the half power switch (60W), I'm at 14W, and for concerts, I put the switch into the full power (100W) position to get the integrated quad firing at about 50W or so...Just for full disclosure, after running the tubes like this for over 6 months, I did have one 6v6 get an internal short and fail, which took out its pair of screen resistors (1k, 2W) which cost me $30 at a tech to get fixed. Could have done it myself for $2 in parts - but I like interacting with techs and he had a tube tester that confirmed the tube was flawed. My assessment was that the tube shorted because that was what it was going to do after bouncing around in my trunk for three hours on the way to a gig, and it shorted immediately upon firing my amp up.

Did I mention you should always have the variac switch on low voltage when using 6v6's, unless you're using JJ 6v6s, which are wayy more robust tubes (and probably not really a 6v6...)?

iN THE way of some technical information for selecting tubes: Plate voltage with variac at low setting is about 372 I believe, with the rectifier to diode, whereas full voltage is between 450 and 460V with diode rectifier. The bias information on the different settings is available on page 8 of the Heartbreaker schematic available on the "schematic heaven" site using the webphix domain.

For reference, the Tungsol RI 6v6 tubes I use were selected by thetubestore.com for use on the EL34 bias setting and 365V plate. I do think they run just a hair on the cold side at the "perfect pair rating" of 23. I'll probably go with 24's or 25's next time around, but they're working out pretty good.

JJ's bias up more like a 16 to 18W tube pair, so perfect pair of 23 is wayyy too cold for the low voltage setting, although they seem to be fairly close for the full voltage setting. Probably 27 would be closer for the low V setting. Just providing some benchmarks so you have a little bit of a benchmark when you go tube shopping.

I'm going to have some bias pots put in so I have a bit more flexibility when it comes to selecting tubes. The going theory is that if an amp is going to be a life keeper, mod it to work for you, and if youre gonna flip it, leave it stock.

And, for the sake of completeness, if you are running a single pair of 6v6s (or el34s for that matter), you should run a 16ohm cabinet from the 4 ohm speaker jack. if you are running a quad of 6v6s or el34s or a mixture, use the 8 ohm jack.

 

[azernebur]

I usually have 6v6's in the outside pair, and EL34's on the inside pair. So when I'm at home on the half power switch (60W), I'm at 14W, and for concerts, I put the switch into the full power (100W) position to get the integrated quad firing at about 50W or so...Just for full disclosure, after running the tubes like this for over 6 months, I did have one 6v6 get an internal short and fail, which took out its pair of screen resistors (1k, 2W) which cost me $30 at a tech to get fixed. Could have done it myself for $2 in parts - but I like interacting with techs and he had a tube tester that confirmed the tube was flawed. My assessment was that the tube shorted because that was what it was going to do after bouncing around in my trunk for three hours on the way to a gig, and it shorted immediately upon firing my amp up.

Did I mention you should always have the variac switch on low voltage when using 6v6's, unless you're using JJ 6v6s, which are wayy more robust tubes (and probably not really a 6v6...)?

iN THE way of some technical information for selecting tubes: Plate voltage with variac at low setting is about 372 I believe, with the rectifier to diode, whereas full voltage is between 450 and 460V with diode rectifier. The bias information on the different settings is available on page 8 of the Heartbreaker schematic available on the "schematic heaven" site using the webphix domain.

For reference, the Tungsol RI 6v6 tubes I use were selected by thetubestore.com for use on the EL34 bias setting and 365V plate. I do think they run just a hair on the cold side at the "perfect pair rating" of 23. I'll probably go with 24's or 25's next time around, but they're working out pretty good.

JJ's bias up more like a 16 to 18W tube pair, so perfect pair of 23 is wayyy too cold for the low voltage setting, although they seem to be fairly close for the full voltage setting. Probably 27 would be closer for the low V setting. Just providing some benchmarks so you have a little bit of a benchmark when you go tube shopping.

I'm going to have some bias pots put in so I have a bit more flexibility when it comes to selecting tubes. The going theory is that if an amp is going to be a life keeper, mod it to work for you, and if youre gonna flip it, leave it stock.

And, for the sake of completeness, if you are running a single pair of 6v6s (or el34s for that matter), you should run a 16ohm cabinet from the 4 ohm speaker jack. if you are running a quad of 6v6s or el34s or a mixture, use the 8 ohm jack.

Thanks for the info! I picked up a couple JJs EL34s yesterday; I love the tone coming out of the Lust channel now, but it seems a bit woofy on the low notes. Here's a sample I just recorded - http://youtu.be/m0M3nn4P3Zk I wish that low end would tighten up. Is this a preamp or rectifier tube issue?

I love that idea of the 6V6s on the outside and the EL34s on the inside. Where do you have the bias switch set?

 

[Tommy_G]

For the 6v6 el34 quad, I have the bias switch at the EL34 setting. The bias applies an offset voltage to the signal hitting the grid of the tubes, and it is the same across all the tubes. So make sure your 6v6s are selected to bias like EL34s as I mentioned above. The 6v6 selection procedure requires finesse and experience.

woofy sometimes comes from an impedance mismatch between output jack and speaker. for a single pair of el34s you should hook a 16 ohm cabinet from the 4 ohm jack.

If that doesnt solve anything, then you will need to tell me what preamp tubes (in order) and speaker you are using, and i;ll try to help you reel it in.

In the way of additional info, The heartbreaker is a full-spectrum voiced amp (flat eq negative feedback loop in the power amp circuit) in the vein of vintage amps compared to a lot of modern amps that have a low cut filter to make a more modern tone. Some of the complaints about the Heartbreaker (with 6L6s in particular) stem from the huge energy levels it has the capabilities to deliver in the lower mid and low freqs in conjunction with full spectrum power tubes (eg, avoid Winged C 6L6s!). The Lust channel is so awesome that you need eL34s to do that channel justice (put it in low or high gain mode with the gain on about 11:00!, mids at 2:30! - gorgeous!). With this in mind, when you search for power tubes, you do not want the ones that have descriptions like Deep Piano Lows.

I use run of the mill Mesa branded (electroharmonix OEM) el34s in the yellow rating and they meet my expectations very well. Mesa branded power tubes have the benefit of being selected for the correct bias range. The Mesa 420 EH tubes are some of the brightest el34s made, they crunch very nicely and cut great. Id guess the new svetlana would also be a good choice, but again, you need experienced tube selectors when you go away from mesa selected tubes.

Dont know much about the jjel34 but I've heard they are a bit on the darker side, and since guys seem to love them in more modern amps....my guess is that they are full-spectrum. This said, none of the big bassy tubes I used ever got me to "woofy". Just to face melting eyeball rattling military warzone type tones. Woofy is different than that. You may want to do some googles comparing JJ el34s to electroharmonix, to see if the woofy could be from your power tube selection.

 

[azernebur]

Before I post a new topic asking if anyone has a used HB footswitch laying around that they'd like to sell, do you have one you'd like to get rid of, Tommy_G?

 

[Tommy_G]

Pretty hard to find an original one. Check out ebay. At minimum, there's a custom pedal switch manufacturer that advertises one for the HB from time to time.

Did you get "woofy" under control?

 

[azernebur]

Pretty hard to find an original one. Check out ebay. At minimum, there's a custom pedal switch manufacturer that advertises one for the HB from time to time.

Did you get "woofy" under control?

I tried the channel switchers from my Mk III, thinking that would work since it's a simple switch box.......no dice. I called Mesa and was told I need the dedicated HB footswitch. I'll search for a used one; if nothing turns up, then I'll try that mfr. I think I know who you're talking 'bout.

As far as "woofy" goes, not yet, but I did find a really nice lead tone in Ch 1 with the Boost off, Curvaceous, Tweed Variac and Tube Rectifier. Then got a nice Plexi clean happening on Ch 2. I think I'm near finding my tones on this thing. I still gotta replace all the pre's and Rectifier tube. The EL34s are definitely the tubes for this amp. She also seems to love my Les Paul quite a bit!

I have some more videos posted at www.youtube.com/theguitarrkidd

 

[Tommy_G]

Ur "Fiddling in E" was totally groovin'....I'm gonna have to hit ya up for a 1/2 day guitar lesson someday!

BTW, smokin tone for the Love Channel. (Please provide all relevant settings!)

 

[azernebur]

Ur "Fiddling in E" was totally groovin'....I'm gonna have to hit ya up for a 1/2 day guitar lesson someday!

BTW, smokin tone for the Love Channel. (Please provide all relevant settings!)

Thanks, Tommy_G - very kind of you. Sorry I haven't responded; was at NAMM today. I've since tweaked the tone on that channel and forgot where I had it set for the video! Will try to dial back in what I had and post ASAP.

BTW, you can check out some of my more serious stuff here - http://youtu.be/mqoupIpuIxM