carvin valvemaster 100 - Speaker pairing? | Warehouse Guitar Speakers

carvin valvemaster 100 - Speaker pairing?

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Pedro Torres
08/13/2018 8:59pm

I did a search for this specific amp and didn't find anything.

Link to manual:

Right now I have this amp head and want to use it for gigging, the gigs that I will play are going to be small bars around town and the amp is going to be miced up, so I don't want to carry around a 2x12 or 4x12 cab. Since it's miced can I get away with just using a 1x12 cab? I was looking at the AMERICAN VINTAGE - 12" WGS12L - 200 WATTS since the amp can be either 50w or 100w. Would this sound good? Or should I try to get a 1x15 since it's going to be a single speaker? and should I get 8 or 16 ohms?

My main focus is to have great cleans, one thing that I struggle with is that on my other amp the highs are very chimey and sound terrible to me. I'm looking for a smoother clear sound.

08/14/2018 7:12pm

Smooth and clear is what the WGS12L is about. The BlackHawk HP isn't as deep, is more 4~6kHz chimey, and might not handle the amp cranked in 100W mode, where it could be reaching ~140W RMS. I'd probably go for the WGS12L over a current production EVM12L. I think it has a bit more high end detail, but still has smooth upper-mids. The clips sound great to me. Anything else by WGS is risky power-wise, and would be more chimey. I say, why not?

I like that the 50W mode of the amp actually cuts out 2 tubes rather than run the set in triode mode. Pentode mode is more dynamic. I imagine is adjusts the OT impedance as well. Not sure how much use the Acoustic Presence control is, seeing that most guitar speakers roll off from ~5kHz, but it couldn't hurt to have it. From what I see of the WGS12L in my SPL graph, it drops down a bit at ~4kHz, has a ET65/90-like ~5kHz dip and then rolls off from ~5.5kHz. That's what makes it smooth with "detail". You can generally turn the Lead Presence up a bit higher with a speaker like that for better 2kHz+ dynamics. I imagine it might be a better match with 5881/6L6GC tubes. Then it's a matter of specifically which tubes for which slots to tailor the response to your taste.

5881 generally break up more like EL34 than 6L6GC, but are more midrange"edgy". JJ are a good current production choice. The Chinese tubes are actually pretty nice"softer" sounding tubes, but not as robust. I'd say it's worth trying a pair of Tung Sol 7581a (6L6 replacement derived from the 7591a "Hifi" pentode design). They are apparently quite robust, and all the reviews are stellar--solid bass like a good 5881, but fuller, warmer, and with a "soft" shimmer. I've gone into preamp tube suggestions b4. I still like the JJ short, medium and long plate type mix, but there are other options for the same type of response. True that tube choices don't make near as much tonal difference as a speaker, but they can add a certain touch response and harmonic character you might prefer.

Pedro Torres
08/15/2018 7:22pm

Thank you for the help. I'll probably pick this one up next paycheck then.

I've heard conflicting things about ohms though. I know my amp can handle 4 8 and 16 but does it really affect the tone that much? I want clarity

08/18/2018 1:16pm

The 12L will certainly rock that rig ... but be prepared, it IS almost the heaviest 12" speaker the world has ever produced :-)

As for impedance ... just make sure the amp is set to match the load impedance and you're good. With tube amps, the issue is that they only perform at optimum standards when the tubes reflect (see) the proper impedance for the tubes and circuit design. An amp with multiple taps on the output transformer (like yours) is designed so that the speaker and output tubes reflect the proper impedance with a variety of speaker load impedance's (ie 4, 8, and 16 ohms)

08/19/2018 10:06am

True dat, Vaughn :-)

My impression is the 12L is a warm/woody/sweet/full sounding speaker, but you'll probably want to break it in at ~1/3 the rated power for some hours to loosen up the surround for the intended tonal balance and sweeter high end. You might use one of those ~$60 Chinese Variacs to do that if you can't play really loud for many hours. It does sound pretty "tight" and a bit top heavy compared to the old EVM12L in Vaughn's marvelous shootout video. I can't find any other demos, but I suspect it will sound superb when broken in. Seems like both that amp and the speaker are sort of "misunderstood gems" that offer more than what one might think. You might even prefer a 2x12" cab with some British type speakers. FI, the Jet City '24SVe' offset slant cab, and maybe replace the top Eminence (V60?) type with an ET65. It shouldn't weigh much more than a 1x12" cab with the WGS12L, and offers better stage monitoring than a 1x12".

You should be able to run just two power tubes in the amp with the power set to 50W with no problem considering that it disables two tubes anyway. Tube pairs are usually configured as the inside and outside socket set. If there's no output from one socket pair, just switch the tubes to the other socket pair. The EL34/6L6 power tube option gives a lot of ways to tailor the amp section sound to your liking. As I say, 6L6GC-like sounding power tubes (including EL34 types like the JJ 6CA7 or the earlier distorting EL34II) might be a better choice with the 12L. The TS 7581a might make the response/feel a bit tighter. It depends what you are after. Those amps are old enough now to at least have the caps checked for leakage, and I'd have the bias set up for a warm clear sound as well. Cold biasing generally delivers a "grungy" sound that can't really be cleared up.

That amp also has DC heater filaments in the V1 and V2 sockets to eliminate any early hum that would otherwise be amplified. The 2.2M Ohm input impedance will make the guitar resonant peak a tad stronger and sharper, but there are a few easy ways to remedy that if it's not to your taste. Just turn the guitar tone knob down bit and/or use a different capacitance cable. It really seems like an overall smart design worth keeping...and tweaking if desired. Some different preamp tube plate length types might be worth a try depending on what's in there--just for subtle dynamic/harmonic-structure fine-tuning. I read that the dirty channel can be altered to SLO100 specs. That might be worth looking into if it's too "fizzy" as is and the mid boost doesn't fatten it to your liking. That and a more beefy Classictone OT might be worthwhile future mods.