Retube Suggestions - Rivera Sedona

Brian · Pit Bull Joined: 26 Aug 2003 Posts: 373

Amp brand and model:
Rivera Sedona 55 combo

Brand and number of tube to replace:
2 - Ruby EL34
5 – Ruby 12AX7 Replaced about 12 mos ago

Aspects of the amp to change or improve:
Used for both acoustic and electric. This amp needs to be capable of getting a rich, full-range tone my Taylor DCSM that has a high end pickup system. It can also get good full or bright (Fender) clean tones in Channel 2 using the Zion with the neck pickup split or not, and I’d like to get lots of harmonics and un-flabby distortion with Channel 1 and when I first got it I was very impressed with the amount of harmonic content of the Sedona over my Boogie MK IIB.
Settings are typically
Channel 1 Volume 8, Bass 8, Mid 5, Treble 7, Master ~ 2, Presence 4
Channel 2 Volume 3 ½ , Treble 7 (Bright pulled), Mid 4, Bass 5, Master 8, Presence 4

My initial thought
5 - balanced Groove Tube 12AX7M Mullard reissues, 2 NOS 'Siemens' EL34s (Matched Pair). Cost about $220 Shocked

again, not chump change to me. Any other suggestions?

Bates15 · Moderator Joined: 19 Feb 2002 Posts: 1084

one repley for both:

You are paying WAY to much! Tubes are expensive but not that expensive! You would be out $500,-- just for the tubes. I found me a sound company with a owner that is absolutly tube fanatic. He fixes my amp all the time. Not even half the price. I can only advise you to look arround, search the net, ask arround at forums for a guitaramp tech that will do things becouse he likes to do it and not doing it to break your bank, or mine....

A fanatic tube engenier will fix you amp and give you some sweet advise at the same time, most guitar stores send the amp to some high priced company and just do what you asked for. Nothing more.

sharring · Tiger Joined: 04 Feb 2004 Posts: 813 Location: Texas

I know i'm way late on this Brother Brian, but have you considered NOS for at least the preamp tubes? They usually last a lot longer than power tubes. And for Fenders, you don't need a great tube in every position, just in a few key ones. Example being the tremolo tube can be microphonic and it wouldnt matter. Maybe check a few other forums, like Webervst and Fender Forum and do some searches. Also, i've bought from a guy named Mike at KCANOS tubes who was fair. His website has some good advice. Be God's-scott

Brian · Pit Bull Joined: 26 Aug 2003 Posts: 373

Thanks Nate and Scott. I just had my Boogie MKIIB gone through. Ruby JJ Selects in V1 & V2 (think they are the JJ type rated the best new production tube at VT Valley), 4 new Ruby JJ 6L6GCs (I think they are the JJs VTV compared favorably to GE gray-plate). The MKII has fixed bias but of course the tech did a thorough checkout and reconditioned the power tube sockets. But HOKEY SMOKES what a difference! Lots of dynamic expression and bite with smooth breakup on the rhythm "channel" with a full tonal range yet the high end just sparkles! Tons of gain, sustain & crisp, tight distortion, no flab with humbuckers even with the bass turned up on the lead "channel". Sounds substantially better right now than my Sedona. $262 parts and labor, feel it's well spent. But I know I paid more for the Rubys through the tech than I would pay for matched/balanced JJs through VTV, Dougs, or KCA.

The Sedona is a real good electric guitar amp; comparable to the Boogie but it really shines as an acoustic amp and whatever tubes I get need to be "musical". That doesn't necessarily/shouldn't mean low gain for V1 & V2.

Mullard 12AX7s go for $210-$300 a pair at KCA or VTV. Ouch!

KCA sells NOS Siemens EL34s (the poor man's Mullard?) for $85 a matched pair. Dougs/VTV sells JJ ECC803s and 12AX7Ss for $35 a matched pair. maybe get a pair of JJs ECC803s and the Siemens?

sharring · Tiger Joined: 04 Feb 2004 Posts: 813 Location: Texas

Bro Brian-I've had real good sound with GE's, RCA's, Mazda's and Tung Sol's (not the Electro Harmonex relabeled ones)-all cheaper than Mullard 12ax7's. Scott

Brian · Pit Bull Joined: 26 Aug 2003 Posts: 373

I did retube the Sedona. Turns out I could not afford NOS tubes even if deeply discounted. I used a GT 12AX7-M Mullard reissue in V1 (drives the "American" channel I set/use for clean electric and Acoustic), a balanced JJ ECC83S (select) in V2 (drives the "British" channel I set/use for Distortion) replacing Sovteks, and matched SED EL34s that were selected for headroom from Dougs. I biased the tubes slightly hot (for a Rivera) at 83.5 maDC

So here's a comparison of the Sedona (GT Mullard 12AX7 reissue, JJ ECC83S, SED EL34s, JBL M121) to my Boogie (JJ 12AX7Ss, JJ 6L6GCs, EV12L) with my 67 Telecaster that has a very wide tonal spectrum.

CLEAN ELECTRIC:
the low end on the Boogie is fuller, without being muddy or bloated, the mids are balanced unlike a blackface's 250Hz notch, and the top end just sparkles! And it has a Great White bite. Smooth breakup. VERY Cool sound.

The Sedona has tight low end, balanced mids and extended highs that can be like an ice pick with the JBL. Smooth breakup. The 4-spring Accutronics reverb tank is MUCH more lush.

Conclusion: The Boogie smokes the Sedona.

OVERDRIVE/DISTORTION:
The Boogie loses some bottom, but that's not necessarily bad. Heavily compressed, loses a little bite. Sustains into next week with a very smooth, tight musical distortion that is just LOADED with harmonics.

The Sedona sounds BIG; almost in your face. The bottom is fuller but tight, and has strong mids, good high end. The sustain is ample but less than the Boogie, with less compression, bite and harmonics. The retube fixed the flabbyness though (YEE HAW!).

Conclusion: I prefer the Boogie but the Sedona is comparable, just different.

ACOUSTIC PERFORMANCE: Taylor Dan Crary Signature Model; a fairly bright & punchy rosewood dreadnaught with an aftermarket high end TrueTone 3-way pickup system (10-100 KHz bridge plate accelerometer, hi & low mics, on board no-cut preamp/mixer). The TrueTone mixer doesn't have an EQ per se. I set the "resonant frequncy" of the accelerometer slightly off from the resonant frequncy of the guitar body to minimize feedback and balance the mic levels with the accelerometer for a very flat response.

Ahhhhhhh, I knew there was a reason I paid $1.8K for this amp. With only a slight downward adj in Treble from the clean electric guitar setting I use, engaging the Parametric and the EV tweeter, there is a big bottom end; slightly more than the guitar's acoustic response, balanced mids, with lots of sustaining overtones and the top end is very "airy". Very clean with no breakup, and volume is nearly what the Telecaster was. I stood a couple feet from the wall farthest from the amp and could hear the coolest stereo effect of the amp behind me and the guitar bouncing off the wall in front of me. And they sounded nearly identical.

SUMMARY:
A little disappointed that the Sedona doesn't have the bite, sparkle, or distortion harmonics of the Boogie for electric guitar. I played with the EQ to see if that made a difference and setting the presence higher than I used to sounds better. But the Sedona's acoustic performance is absolutely stellar; big, warm, punchy, and airy, and very natural sounding. I am delighted that the distortion tightened up so nicely with the retube. I might try setting the Sedona's bias a little higher but then again, I LOVE the acoustic performance so I might not.

2 very nice amps, prefer the Boogie for electric; it's a killer amp. But the Sedona is the best acoustic amplification system I've heard (maybe #2 behind Daedalus) and still a good electric guitar amp.

sharring · Tiger Joined: 04 Feb 2004 Posts: 813 Location: Texas

Excellent review. I've read that the GT 12ax7 is a little more lacking in mids than the JJ...is that why you chose the GT tube for the clean channel?

Brian · Pit Bull Joined: 26 Aug 2003 Posts: 373