Jazz tube amps

[Jerry Turberville]

Has anyone tried the Rivera Jazz Suprema amp with their emando? If so, did you have the 12 or 15 inch speaker and what did you think about it? Besides opinions on the Supreman, I'm also curious as to what affect the 15 inche speaker has on the emando tone.

I've been trying out a few different tube amps lately, but haven't been able to locate a Rivera. Surprisingly alot of the amps I tried sounded thin, at least to me. I was downright disappointed in a few. There were a few nice ones.

Ed mentioned a while back, how much he liked the Blackheart handsome devil, so I made it a point to track that one down. Although I didn't particularly care for the tone it was a lot nicer than several of the other more expensive amps. It's a very nice amp. IMHO I feel it lends itself best to a rock or blues type sound.

A friend wants me to try his Fryette Deliverance amp. So, I'm going to borrow it Friday night and compre to the Fender amps I've been using. This is just my attempt at the never ending search for that seemingly elusive "perfect" tone. Thanks for reading.

[Ed Goist]

Hi jlt; thanks for starting this thread, I'll be watching it with great interest.
I would completely concur that the Blackheart is fundamentally a rock and blues amp. No doubt.
Please keep us posted with updates of any other amps you try.
..."elusive 'perfect' tone" is right!

[rico mando]

so what kind of jazz pickups are you pairing with your jazz amp ? no tubes in this . but you may find the tone your looking for

[Jerry Turberville]

I owned a Roland JC120 and it is a really nice amp. I'd like to have another one someday, but as nice as it is, it doesn't have the warm tone I like. I didn't mention earlier I tried a few of the Roland cubes with the amp modeling built in. They're very good, but fall just a little short. I think that is just the tube vs solid state thing. I'm do prefer tubes. Evans, Henriksen, Polytone, and Jazzkat, to name a few, all make excellent amps. It's just not quite the sound I prefer.

I have the Kent Armstrong jazz pickups in the JLSmith emando and I'm not sure about the pickups in the 5 dtring Fender FM 60E. I know they're not the stock pick ups. They are less tinny and have a fuller darker tone than the OEM pickups. I hope that makes sense. Steve Ryder is building a 5 string for me now and it will have his hand wound pickups. The hand wound pick ups were one of the best things about the Roberts emandos.

The tone I'm getting now is pretty good. The two main amps I'm using are a Fender Twin and a Fender Concert (1994 model). There's a lot of headroom in both amps. I can dial in a rich warm tone that's bright, but not overly crisp.

I know there's more to the tone than the amp and pick ups. There's some wonderful subtletries that can be achieved with proper pick control (attack, angle etc). I hope to have that kind of control someday. I know it's a big portion of the end product. The tone is not coming from one thing, but rather a succession of thing. The amp and speaker are, more or less, the last thing in the chain.
Do you have a recommendation for a jazz pick up?

[rico mando]

sorry i have no recommendation for a jazz pick up . have you tried using compression in your signal path . if the amps you have are " pretty good" maybe some descent compression or eq or a BBE sonic maximizer

as i do not know what tone your looking for i am just firing out random suggestions in case there is something you may have overlooked . i am 100% behind your quest for the right tone . I like to use EMG active pick ups

[Charlieshafer]

I

I know there's more to the tone than the amp and pick ups. There's some wonderful subtletries that can be achieved with proper pick control (attack, angle etc). I hope to have that kind of control someday. I know it's a big portion of the end product. The tone is not coming from one thing, but rather a succession of thing. The amp and speaker are, more or less, the last thing in the chain.
Do you have a recommendation for a jazz pick up?

Nah, Jimi Hendrix used to say he didn't play guitar, he played amp. Just keep trying things like Carrs and Swarts, 65's and stuff, you'll find one you like. How loud do you need it to be? The higher the wattage of the amp, the more you have to push it for that nice fat tone. Some of the sweetest amps have lower wattage ratings, 20-25 and below. Don't forget the huge powered amps were for arena-sized venues. You playing for 20,000 people? If so, there's always Marshall...

[Pete Martin]

I recently found a mid 70s Princeton reverb which works great with my Mann EM4.

[Charlieshafer]

I recently found a mid 70s Princeton reverb which works great with my Mann EM4.

THAT'S a great amp.

[Jerry Turberville]

No, I don't need a lot of power. Ideally I think 25 to 40 watts would be more than enough power. The Rivera Suprema is a 55, or 60 watt amp. One thing I don't want is a 10 inch speaker. Almost every amp I tried with a 10 inch,, or smaller, speaker sounded weak when compared to a 12 inch speaker. I have a little super champ (stock 10 inch speaker) and when I run it through a good speaker cabinet with 12's it sounds like a different amp.

I'd borrowed a Princeton amp for a fiddle gig many years ago and remember I liked it a lot. However, I was disappointed when I tried a used one at the local guitar center with my emando. It sounded thin with the emando. I think ithe amp was a mid 80's model and I detected some scratchiness in the controls. It was also a bit noisy when I was there. When I tried a Hot Rod Deluxe sitting next to it I got a nice full sound, so I don't think I can blame the excess noise for the poor tone on that Princeton. I think that particular amp had something wrong with it.

[Pete Martin]

What era was the Princeton? The solid state ones sound WAY different from the older tube amps.

When I first got the Mann, I tried a LOT of tube amps in stores. I found most of them to be harsh and brittle. I settled on a solid state amp that was inexpensive and sounded decent. I had given up on tube amps until a friend suggested a few vintage models. I found this certain Princeton sounded WAY better than all the others I tried. The fact that the guy only wanted $300 was also a selling point

[Jerry Turberville]

It was an older tube model and similar to the one I'd used once before. I think there was something wrong with the amp because I recall them being a good little amp.

[rico mando]

It was an older tube model and similar to the one I'd used once before. I think there was something wrong with the amp because I recall them being a good little amp.

Probably needs new cones and a few other new parts .

[SternART]

Or possibly tubes......their sound changes over time, as they slowly go.......

[Verne Andru]

A lot of the modern jazz cats play solid state amps. People like Wes Montgomery played tubes because that's all there was back then. When I listen to his recordings I can hear the sound of a jazz box through a tube amp, and it's not the best tone IMHO.

Mike Stern, as one example, uses an older Yamaha G100 212. It's a 100 watt solid state amp with a parametric EQ - which is fab for dialing in a good tone. I have the 210 version and it's fabulous for a clean, clear jazz tone.

Quite a few of the modern tube amps are designed for rock and distort easily - not what you want in a jazz setup. You may be better off with a SS acoustic amp than tube IMHO.

[Polecat]

I have a Fender Super Sixty (designed, for what it's worth by Rivera) and a 15 W tube Amp I built myself, having found it impossible to find a guitar amp that gave me a tone that I was happy with. The Super Sixty is in the attic waiting to become a "collectors item" so that I may one day be rich. 15 W is, in my opinion, plenty loud enough for a mandolin - to get a decent sound, be it a jazzy tone or something rockier, the output valves need to be doing at least some work, and with anything more powerful, I find that hurts the ears (I sometimes even use a couple of high-power resistors as a power brake between the amp and the speaker). The problem with finding an amp for an emando is that there literally aren't any - Leo Fender built his first amps based on radio circuits, then modified them to make an electric guitar sound good; everybody else copied him (with admitted exceptions). Nobody has done this for mandolins, so the amps end up sounding less than optimal (imagine shortening a guitars neck, fitting it with 8 strings and expecting to get a good mandolin as a result). Fortunately, although a lot of voodoo is talked about "modding" and "hot-rodding", there are some measures one can take without having to completely rebuild the amp. One (at least with low-powered amps) is to disconnect the negative feedback loop - this usually runs between the speaker side of the output transformer and the phase-splitter (the last tube stage before the power amp); if the amp has a "presence" control this is almost always in the negative feedback loop, and disconnecting the sweep connection of the pot. will break the circuit. In my experience, an amp thus treated sounds "livelier" and more responsive. The Vox AC30 is a good example of a guitar amp that gets along very nicely without a negative feedback loop, although I believe it's a bad idea to play a bass through an amp thus treated. The other simple thing one can do is to shift the frequency of the "middle dip" that all guitar amplifiers (at least those based on Fender's design) exhibit.
The tone controls in a guitar amp look something like in this diagram

The values of the components may vary, but typical (Fender) values are R1=100k C1=250p C2=0,1y C3=47n.
Increasing the value of R1 and decreasing the value of C1 has the effect of raising the frequency if the "middle dip", which I found to give a more mandolin-like tone to the amp.
I would like to add that I am not an expert - these are only my own empirical observations on a very limited range of amplifiers (3, to be precise), also I'd like to point out that even in an unplugged valve amplifier, there may be potentially lethal voltages, so it's best to thoroughly inform oneself before attempting to do anything. On the other hand, it's not rocket science; I would encourage anyone with an interest in "a better tone" to at least have a look at the inside of his/her amp, because I found it a lot of fun.
If anyone is interested in the circuit diagram of the amp I eventually built myself, I would be happy to send it to them.

[Polecat]

I forgot to mention in my last post that in the tone control circuit, P1 is "Treble", P2 "Bass" and P3 "Middle" - makes sorting out what's what a lot easier if you haven't got a schematic for your amp.

[Jerry Turberville]

I might give that a try. I did pull 2 of the power tubes and disconnected one of the speakers (in my twin). I rarely play past 3, and usually have the mando volume below 5. When I did turn it up to test the tone there was a slight diffference. I've been trying to find a lower wattage amp, but haven't found anything I like. I'm thinking 15 to 25 watts is more than enough.

Something else I'm considering is trying a pair of weber california speakers, or the eminence combination of a canabis rex and the red white and blues speaker. The later is proported as having a "dark silky smooth tone."

I'd also thoiught about buying an amp kit, but the ones I looked at seemed overpriced. I haven't taken the time to look for the parts separately. Did you build a class A circut?

[Polecat]

The amp I built has 2 EL84s running push-pull in class AB. One day when I'm grown up I'd like to build a class A Amp with 2 EL84s as a single-ended design, but that's for when I've really got a lot of time. I agree with you that amp kits are overpriced, but when you add up the cost of the components (particularly power and output transformers), there's no way to build an amp from scratch on the cheap.
Another option is to buy a cheap low power amp and use it to experiment. I have heard a lot of good things about the Harley Benton GA15 - I've no idea how they get the thing built (even in China) for that price; as I say, I couldn't even buy the components for that, and shipping to the USA is 30€, which is reasonable. Knowing what I now know, I would probably buy one, and if I wasn't happy with the sound, rebuild the amp over the printed circuit board with point to point wiring - that way I could use the chassis layout as is without having to do any mechanical work (planning the layout of my chassis was one of the most time-consuming parts of the project).
Interesting that you don't like 10" speakers - I do - I've plugged my amp into 1X12, 4X12 and 1X15 cabinets, and I find an open-backed 1X10 with a Celestion G10-S50 sounds best to my ears - larger speakers seem to compromise the pick attack, which bothered me (again, this "I want to sound like a mandolin, not a high-pitched guitar" thing!!). I neither understand nor believe the ad-speak used to promote amps or speakers (what does "silky" sound like?); I think the best approach is internet research what other people have found good, and trying things out (ideally in a music shop, though that's not always feasible - I was once asked to leave after spending 11/2 hours in the soundproofed "Amp cabinet")

[rico mando]

A hotplate(attenuator) between the output and the speaker is used by many guitarists to bring their amps down to apartment volume levels but still retain distortion/ high volume tone

[Sea Lion]

It's been a while since the last post on this thread. But just in case anybody is interested, you may want to contact the folks at SOUNDISLANDMUSIC.COM. They've developed several Jazz voiced tube amps that might work nicely for your mando.