Rockin Daddy
10 posts
Sep 30, 2015
12:51 PM
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I know there's plenty of discussions about Bassmans but here's what I need help with. I have a Bassman Reissue LTD, bone stock except for preamp tube swaps and Power tubes swapped. My question is, taking the player out of the equation, what makes a bigger difference on the tone of the amp, power tubes or speaker swaps? I just can't get a warm, smooth tone, it always seems to be too harsh and a little too cold for my tastes.
Here's the stats of the amp:
I plug into the #1 Normal channel with an Astatic crystal
Bright Volume is off-all the way down
Treble-3.5
Mid-3
Bass-8
Presence-5-6
Rectifier tube-stock Ruby 5AR4
Power Tubes-JJ 6L6GC
Preamp Tubes-1st: GE 12AY7, 2nd:JAN 6072, 3rd: stock GrooveTube 12AX7
Speakers-stock Jensens P10R
Would changing the power tubes to something besides JJs warm up the tone or would swapping the speakers out be a better route? I know all the basics about tone coming from the player, but taking the player out of the equation, is there anything in my setup that would make my Bassman sound too harsh and cold?
All suggestions are welcomed.
Brian
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1847
2783 posts
Sep 30, 2015
1:05 PM
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is the mic a vintage crystal, or the newfangled recent one?
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Kingley
3936 posts
Sep 30, 2015
1:11 PM
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Hopefully Mark Burness (5F6H) will come along and add his wisdom to this thread. He is the man when it comes to setting up Bassman amps for harp.
I'd imagine that speaker changes would give the most drastic change without doing circuit mods. Many people change two of the speakers and run two ceramic speakers and two alnicos I believe. Another thing to bear in mind is what the valves have been biased too. That will affect the tone as well I think.
Other than that turn your bright volume 5 or 6 and then set the normal volume to where you can get it, before feedback. As the bright volume affects the tone of the amp as well. Even if you're only plugged into the normal volume. Also try a jumper cable from normal volume 2 into bright volume 1. Those things may help until Mark comes along and gives you some definitive advice.
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Rockin Daddy
11 posts
Sep 30, 2015
1:17 PM
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1847-the mic is a vintage crystal.
Kingley-I have tried the bright volume and jumper route, seems to add more to the coldness in the sound. The amp guy rebiased it when he swapped the power tubes, there's a sticker on the tube box that he wrote 18/2.6. not sure if that helps in deciphering anything, it's over my head.
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tomaxe
56 posts
Sep 30, 2015
1:27 PM
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I'm sure you'll get some expert advice on this forum about how to tweak the guts of the amp. However, your settings and tubes sound about right as a starting point from a layman's viewpoint. Treble down, bass up, lower preamp tubes, etc. etc. Barring the "tone comes from the player" cliché—which, like so many clichés, has a lot of truth to it, I find some crystal mics to be a little brittle and mid-rangey to my ear unless you are a REALLY solid mic cupper and have big tone. Perhaps try a CR/CM element in your Astatic, or even an SM57. Big bass.
Also, the Jensen speakers are also very mid range oriented. Again, good for some players, not for others. Talk to someone at Weber speakers and see what kind of affordable mix you can get to give you a warmer tone.
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barbequebob
3035 posts
Sep 30, 2015
1:41 PM
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If anything when it comes to 4-10 Bassman amps, based on the fact that I own the real deal rather than the reissues, for the power tubes, 5881's are wht should be there and the only really good new production ones are the Tung Sols reissues and the TAD 6L6GCWC, both of which have a shorter bottle, less treble, more bototm end and mids.
For the 2nd pre-amp tube, I'd never use a 12AY7/6072, but my hands down favorite is an NOS GE 12AX7 with the long plates made from the late 50's to early 60's, and then for newer production tubes, either a Mullard or Tung Sol reissue. On the 3rd preamp tube, Either of those or a NOS Sylvania, but the GT's are terribly overrated in their present production.
I personally dislike ANY of the tubes made under the Ruby and Sovtek brand names and I wouldn't use them in any amp.
Nothing beats an NOS Mullard 5AR4 rectifier tube at all, which isn't cheap but they are better overall and will last YEARS longer than anything presently in production, but if I were to use a newer production 5AR4, I'd either get one made by TAD, JJ, or a reisssue Tung Sol.
The present production of P10R's when compared to the originals absolutely suck big time and I'd rather have, in terms of present production, either a Weber 10A120, or an Eminence Legend 1028K, or if you can get a hold of a set of the blue painted Eminence Legend 102's that were used on the 1st Bassman reissues, but if you got the money and can find them that haven't been messed with, an original Jensen P10R or P10Q. The newer P10R's are much more trebly and stiff than the real deal, but if you prefer to use newer Jensens, the P10Q's are a better choice.
Here's how I have my real Bassman's tone controls set:
Normal volume -- 2-1/2-3
Bright volume -- 6
Treble -- Totally turned off (set at 1)
Middle -- Anywhere from 3-4
Bass -- 6 but never higher than 7
Presence -- 8
If the amp is biased for a 6L6, the one tube in newer production I'd use would be a Tung Sol 6L6GCSTR reissue, which has a sligthly louder output and can take a higher voltage than a 5881.
I personally hate the channel jump thing.
However, the single BIGGEST mitigating factor is ALWAYS going to be the player's own personal acoustic tone no matter what you do.
I've owned that real Bassman since 1983.
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Sincerely,
Barbeque Bob Maglinte
Boston, MA
http://www.barbequebob.com
CD available at http://www.cdbaby.com/cd/bbmaglinte
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5F6H
1889 posts
Sep 30, 2015
2:26 PM
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You need to change some, or all, of your speakers, not really any way around that one, the new Jensens are thin & metallic.
Also try a 5U4G rectifier, softer than the 5AR4/GZ34.
I don't think the JJ power tubes are a good match for this amp, I prefer the Sovtek 5881WXT over pretty much anything available current stock, mybe try some Phillips 6L6WGB if you have money to spare. Get the bias checked, with the Sovteks 7 to 15mA per tube would be good.
I would keep preamp tube swaps to the first & maybe second preamp tubes (V1 under the inputs & middle preamp tube) there are a couple of resistors prone to burning up if low gain preamps are used in V2 & V3.
Again, none of these changes will make a great deal of improvement without changing the speakers.
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www.myspace.com/markburness
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1847
2784 posts
Sep 30, 2015
7:36 PM
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i run a pair of mojo tones which are if i am not mistaken the same as the Legend 1028K, cept with extra mojo.
the other two are a re-issue p10q smooth cone
and a vintage p10q re-coned
i used a loop pedal to break in the new jensen
i like how they sound, not sure if they were all re-issues i would feel the same.
i have been meaning to install 2 vintage p10 r's that i had re-coned just because they are sitting on a shelf behind me, just begging to be heard.
however i would love to hear how a tone tubby low watt hemp cone speaker would sound. just cannot justify buying anymore speakers. what i have works. at some point chasing tone is futile. but 4 new jensens may be a bit nuch
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TetonJohn
273 posts
Sep 30, 2015
7:54 PM
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Do you happen to have access to a Lone Wolf, HarpTone+ pedal? It would be interesting to see what you thought of that (among other things, the pedal would help match your crystal microphone impedance to the amp).
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shakeylee
395 posts
Sep 30, 2015
9:18 PM
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everybody is so quick to mod! i find i can get a decent sound out of most bassmen.
i've played real ones,early reissues , new ones,clones,vickies.
i own an early reissue.i keep a 12ax7 in p2.
one thing i sometimes do is turn the mids all the way up and treble all the way down.
also,i use a kinder.
i have boxes and boxes of NOS tubes,but i think people get too hyped up on this stuff.
if you live near philly,bring it to my house.we'll go through some NOS tubes and try some different mics.
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www.shakeylee.com
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shakeylee
396 posts
Sep 30, 2015
9:20 PM
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please be advised: mods are usually set ups that make an amp sound good at bedroom levels. when you play on a large stage, you want that 12ax7!(for example)
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www.shakeylee.com
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5F6H
1890 posts
Oct 01, 2015
5:33 AM
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"please be advised: mods are usually set ups that make an amp sound good at bedroom levels. when you play on a large stage, you want that 12ax7!(for example)"
That's just not true.
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www.myspace.com/markburness
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6SN7
574 posts
Oct 01, 2015
5:56 AM
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I'd swap out the speakers. Those new Jensens are not so great. Some NOS alnico Jensen P10R or P10Q speakers would be cool, or maybe 3 of those and a ceramic speaker. Also, NOS tubes are the way to go, IMHO.
Good luck and have fun!
Last Edited by 6SN7 on Oct 02, 2015 7:58 AM
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1847
2785 posts
Oct 01, 2015
7:30 AM
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the re-issue bassman does not require any significant mods. some people do not like the speakers
but that is a personal preference. if i remember correctly, mark baier, at victoria amps uses the jensen re-issues.
at one time i owned a re-issue bassman, it was stock
although i did change the tubes, because i had nos tubes sitting around.
also i seam to remember lester butler used a re-issue bassman that was also stock.
i think its time to dig up a little lester butler
i need to hear some of that today
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harpwrench
1027 posts
Oct 01, 2015
8:03 AM
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I got an LTD a little while back and it sounds great. It has a 5751 in the middle hole and I think the prior owner might have changed the rectifier/rebiased, but speakers and circuit are otherwise stock. It sounds nasally if the mids are turned up much, or maybe I should say I sound nasally. I run treble at 6 and presence at 9 or so though. Finding a mic element that compliments your personal tonal signature is IMO a key part of it.
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www.spiersharmonicas.com
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Kingley
3937 posts
Oct 01, 2015
9:39 AM
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I've owned two Bassman LTD amps. The only change I made to both was to put a 12AY7 in V1. They always sounded fine too me and plenty warm enough. I used a JT30 with a 99A86 CM element.
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5F6H
1891 posts
Oct 01, 2015
10:24 AM
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As long as an amp is reliable & not going to go up in smoke, no amp requires modification, you don't even need to use a tube/bassman amp. But if you have spent money on an amp, make it how you like it. It's only job is to sound nice, if it's not making you happy, try changing a few things that won't break it.
Stock amps with changed tubes, anti-feedback pedals & speakers aren't "stock" anymore, voltages & currents change, you can see over 50vdc difference between different bassman's power tubes...even if all the tubes & settings between these amps were identical, that alone makes a vast difference in the sound.
One man listening to one amp may have different perception of the sound to another elsewhere with another amp of the same type...it maybe their perception, but it will often be because they are quantifiably different.
Rant over :-)
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www.myspace.com/markburness
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shakeylee
397 posts
Oct 01, 2015
8:35 PM
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you are right.i should have said "most mods i have come across."
over and over again i see or hear amps wherein the accomplishment is an amp that breaks up at a lower volume.
i should have clarified.
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www.shakeylee.com
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1847
2790 posts
Oct 01, 2015
9:23 PM
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if you change the tires on a 59 cadillac
or perhaps change a broken string on a 57 strat, you could argue
that it is no longer stock.
but if some one changed a 5881 with a nos tube
how would you prove it was not a stock tube?
four flat tires on a caddy is another story.
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5F6H
1892 posts
Oct 02, 2015
2:12 AM
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@1847 "but if some one changed a 5881 with a nos tube
how would you prove it was not a stock tube?"
Let's perhaps assume "stock" means manufacturer intended performance?
I was thinking more about preamp tubes, maybe rectifiers too, but any different spec/brand tubes will pull different currents & therefore different voltages.
A vintage NOS 5881/6L6WGB may pull 50-60mA per tube in pre LTD RI with a non adjustable bias vs half that for a Sovtek 5881WXT, voltage will follow the current draw. RIs have different PTs to the originals (& even each other), more variability & different bias tap voltage to originals.
In a Fender preamp section with a 1500ohm cathode resistor and 100K plate resistor a 12AX7 tube will show ~67% of the B+ voltage at that stage, on its plate, a 12AY7 ~49%, a 12AU7 ~30%. Without changing any resistors in the amp & just changing a preamp tube, you can half the plate voltage of a given stage, that's a pretty significant 'mod', equivalent to keeping the same tube in place & changing a power supply resistor by x10 in value. RIs never came with a 12AY7.
I personally don't hold much store by the phrase "stock" simply because of the variance in production tolerances (though the RIs have actually been the longest run of Fender 5F6A bassmans without changes to the audio circuit, the originals had about a dozen permutations). Most people make these assumptions on what they can see rather than measure/hear, people like to overlook mods that they just don't consider mods, despite the fact they have made deliberate changes.
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www.myspace.com/markburness
Last Edited by 5F6H on Oct 02, 2015 2:21 AM
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Hakan
523 posts
Oct 02, 2015
3:32 AM
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I agree with 5F6H. When I bought my FB Reissue last year I switched to 5U4 and it was smoother. I also have 12AU7 in 2nd.
I also switched one lower speaker to Jensen C10/40 Falcon 10" 40W 8 Ohm that produced a warmer sound:
http://www.tubeampdoctor.com/en/shop_Jensen_JET_SERIES/Jensen_C10_40_FA_10_40W_8_Ohm_ZJ05451_2894
It's probably my cupping technique but crystal is not my favorite for my FB. CR sounds better. Ultimate/Shure SM57/SD545 is the best.
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