Lonestar bias mod

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plan-x
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Re: Lonestar bias mod

Post by plan-x » Fri Jul 23, 2010 3:39 pm

djw wrote:Cool. Sounds like this is what the Stiletto has always needed...
I'm still trying to figure out why charles bought one?
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Charles Reeder
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Re: Lonestar bias mod

Post by Charles Reeder » Wed Jul 28, 2010 2:20 pm

Hey plan-x:
Why would I even want a Stiletto? I really would have figured you to know the answer to your question; but I'll spell it out.

I like 'classic' rock, blues, country sounds; mostly from the late 50's to mid 80's...and Fender and Marshall were featured hugely in those sounds. I have had almost every model Fender amp from early 60's on as well as the Super Lead Marshalls from early 70's on; and a few versions of the JCM 800's...both the 1-channel master volume and the 2-channel switchable version.

My last Marshall (which I just got rid of was a JCM 800 2x12 100 watt 2-channel combo). With my shoulder surgery and advancing age; I wanted to go the head/cab route. So, I decided to give a Mesa a try.

It was my guess that the Stiletto would be to the 'Marshall sound' what the Lonestar was intended to be to the 'Fender sound'...not an exact copy; but a stylized approximation with some new and useful features.
Well...for the most part it is...at least to me the pre-amp section seems to be voiced very close...but in the case of the Stiletto; it's in the power amp section where the amp falls short due to the cold bias situation. Channel -1 of the Lonestar is great as is...whereas as we all know....I was unsatisfied with channel-2 from the factory. Well, I worked out that problem. The 'fix' for the Stiletto was actually simpler...the pre-amp was already pretty close to several 'classic' Marshall sounds. (close enough for my purposes anyway).

The bias-mod (which I think both amps benefit from) was all it took for the Stiletto...but it needed that mod WAY more than the Lonestar did.

I am now perfectly pleased with both amps.

Like most guitarists; I am driven both consciously and not-so-consciously by GAS...and I don't mean the kind aquired from the intake of beans.
My 'ideal' setup is to use both the Lonestar and the Stiletto with an 'amp switcher' between them. BTW; no disrespect meant; but I am not doing so to emulate a very well-known guitarist's use of the same 2 amps...my style and aims are very different.

Anyway; before I got the bias situation fixed on the Stiletto I had only used the dual amp setup about 3-times; as it simply had to be run very loud to sound right. I anticipate more opportunities to use it now. I will admit however; that I will still use the Lonestar alone...way more often than the dual amp setup. About 80% percent of the stuff I play calls more for the Lonestar sound...but there are a few selections which simply 'scream-out' for the Stiletto; and for those few selections; the Stiletto makes the song!

Being honest though; I simply love an excuse (good, bad, indifferent, silly, logical, illogical, or even downright stupid!) to buy and try another piece of equipment!

My guess would be that most of the readers of this posting can empathize somewhat (to a greater or lesser extent) with my equipment obsession!

Cheers, Charles

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plan-x
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Re: Lonestar bias mod

Post by plan-x » Wed Jul 28, 2010 4:08 pm

Ok Charles, I dig. All I know is when I demo'd the stiletto a couple of years ago, I couldn't see myself taking that amp home as it didn't fill the room like the LSC. It just sounded kind of sterile. JCM 800 it was not. So kudos to you for doing what you do and bringing the best of that amp out of power amp deep freeze. :lol:
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splatter
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Re: Lonestar bias mod

Post by splatter » Wed Jul 28, 2010 8:22 pm

dont want to get way off the subject here but I just don't get why everyone likes the jcm 800
. I have owned 2 and couldn't get the sound I wanted from either one . I understand they are a good platform for pedals but so are alot of other amps. My first marshall back in the early 80s was a plexi and the 3 or 4 that followed were plexis as well .So to me a marshall shouldn't need a pedal to get that screaming marshall tone . Just the way I came up I guess . I still wont buy an amp that I have to use a pedal to get the sound I want . The only pedals I use are delay and reverb .

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Re: Lonestar bias mod

Post by Charles Reeder » Thu Jul 29, 2010 12:53 pm

plan-x (and) splatter:

I guess we have gotten a bit off the (main) subject...but...all this does bear to some extent on the idea and purpose of the 'bias-mod'.

In essence...I agree with the statements above from both of you.

plan-x:
Had I the opportunity to try out a Stiletto (I didn't...I bought one never having heard one; just as I did the Lonestar)...I would have agreed about your observation that it sounded 'sterile'. It did...but the 'bias-mod' fixes that problem up nicely. As for you preferring the sound of a JCM 800...well...the Stiletto now...in my opinion; sounds SUPERIOR to the JCM 800 that I just sold (after having the mod done).
splatter:
I had the 'plexi's too...and they're the ones I consider the 'real' Marshalls! After all they were the ones that helped establish the 'tone standard' that 'rocked the world'. I bought a JCM 800 100 watt (single channel master volume head) some years after having owned and sold my plexis. That JCM 800 DID sound very convincingly ' Marshallesque'. There were definitely good sounds to be had from the channel switcher JCM 800 combo that I just sold...but it lacked that certain indefineable 'something' that the others possessed. I find that the Stiletto (after the mod); with some pre-amp tube changes and careful control tweaking is capable of matching my favorite Marshall tones quite convincingly.

For those who have tried and been disappointed with the Stiletto in the past...this mod (the adjustable bias 'Mansfield kit') would probably get most players to the place they hoped to be with the Stiletto.

BTW: I want to say something about the fact that 'Mansfield Guitars' offers these kits .
You may have noticed...most techs who have done various mods on both the Lonestars and Stilettos WILL-NOT-SHARE their knowlege so that we can do these mods ourselves. They guard every bit of info the same way ancient alchemists guarded their formulas. Certainly (not unreasonably); they want to make some money off of the mods...but they aren't going to get that many amps sent to them. Most players just aren't willing to spend the kind of money (2-way shipping plus parts and labor) and the 'down-time' while the amp is away on a mod they haven't heard. Because of this; I can comfortably say that Mansfield's decision to offer these mods in kit form not only helps us players tremendously...but is also a really good business decision!
Mansfield; not only provides the parts as a kit in a cleverly pre-constructed unit ; but provides clear instructions and photos to guide you through the whole process. This is invaluable! For about the cost of a pair of output tubes; you get a kit PLUS the info that suddenly makes ANY sets of output tubes you happen to already own usable in your amp. I have spent far more time (and money) trying out different grades (or color-codes) of output tubes in an attempt to get the output stage properly warm than the cost of the kit. More importantly; I did not get the great results that I obtained from the kit!
Whether you are considering a bias kit for a Lonestar or a Stiletto (or any of the many other amps that Mansfield offers a kit for); I recommend that you buy it. It's worth far more in the longrun than the price of the unit itself ...and effectually improves the sound of your amp many times over.

I want to personally thank Mansfield for making these kits (and the accompanying installation information) available to us.

Regards: Charles

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plan-x
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Re: Lonestar bias mod

Post by plan-x » Fri Jul 30, 2010 2:45 am

Now you've done it Charles! :x With your endorsement of this, I'm gonna have to give this a whirl. Here we go again! (Thirsty Pirate's famous words). And I'm really enjoying my rig right now. But no....gotta GAS some more. Thanks splatter :x :mrgreen:
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Re: Lonestar bias mod

Post by thom » Sat Aug 14, 2010 6:10 am

Does anyone know if the Lonestar adjustable bias mod would work on an LSS and if so if it would be a worthwhile mod. I did read on the Eurotubes site that the Mesa EL84 amps are biased hotter than the 6L6 amps. I do like the tone of my LSS fitted with JJ output tubes (NOT JJ preamp tubes though) but I do like tinkering......

Thanks

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Re: Lonestar bias mod

Post by Charles Reeder » Sat Aug 14, 2010 11:45 am

Would a 'bias-mod-kit' work on the Lonestar Special? HMM....good question!

If they have a set of schematics for the LSS; then Mansfield Guitars; who made the Lonestar Classic and Stiletto 'bias-kits' which I have installed (as well as other kits for other amps) would know.
Contact John Mansfiled. If they don't have a schematic...try and get one and forward it to him. He tells me that Mesa is far more likely to share a schematic with a Mesa owner than a freelance technician.
If the LSS can use one, and benefit from it (a bias-kit); he'll make one up for you!

Charles

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Re: Lonestar bias mod

Post by thom » Sat Aug 14, 2010 12:37 pm

Thanks Charles. I will drop John a line and see what he says.

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Re: Lonestar bias mod

Post by splatter » Sat Aug 21, 2010 8:13 am

thom wrote:Does anyone know if the Lonestar adjustable bias mod would work on an LSS and if so if it would be a worthwhile mod. I did read on the Eurotubes site that the Mesa EL84 amps are biased hotter than the 6L6 amps. I do like the tone of my LSS fitted with JJ output tubes (NOT JJ preamp tubes though) but I do like tinkering......

Thanks
I don't think it will work . The lss is a class A amp isnt it ? if I understand class A amps correctly they are cathode biased and therefore the mod won't work on it .

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Re: Lonestar bias mod

Post by thom » Sat Aug 21, 2010 12:45 pm

I am no expert but I am pretty certain that the LSS is not cathode biased.

Regards

Tom

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Re: Lonestar bias mod

Post by ja22y » Wed Sep 01, 2010 10:40 am

According to the man himself in this article, the LSS is Cathode biased.
http://www.premierguitar.com/magazine/i ... oogie.aspx

"Is your entire guitar amp line up now fixed bias?

Randy: Almost, the Lone Star Special is the one amp that’s cathode biased, meaning it doesn’t have a fixed negative-voltage bias supply. Most people call cathode-biasing Class A because it sounds sexier. When asked to explain this, and the difference with Class AB, it ran to about 30 fun-filled pages available on our web site (mesaboogie. com). But there is another common meaning for fixed bias, and that’s when the negative-voltage supply is not user-adjustable, and we do that too. All our negative bias supplies are fixed at the factory, that is, they’re wired to supply the correct voltage, and never need adjustment."

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Re: Lonestar bias mod

Post by thom » Thu Sep 02, 2010 1:06 pm

Wow, very interesting. When ordering output tubes my supplier has always made a big deal about selecting ones for a Boogie when I told him I had an LSS. Don't think I was ever charged any extra but still.........

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Re: Lonestar bias mod

Post by alie123 » Mon Sep 27, 2010 8:18 am

Hi Lonestar fans, I have a question about the Bias mod, hope you can help me ..

I also have the Mansfield bias mod, (for my Stiletto ACE) I have some strange things. I am curious what you guys have experienced when installing the bias mod.

I have the mod not yet installed, because first before installing the mod, I was measuring with the Mansfield bias probe how 'cold' my amp was. What I found out was weird.

Clean modes (fat clean, tite clean) are stock biassed much higher then the overdrive modes, so In what mode have you set your amp when biassing with the Mansfield bias mod? (I don't want to blow my amp)

For example: with fat clean & tite clean I measure about 38 to 42 mA (depending on what tubes I installed)
and when I switch to channel 2, I measure about 30 to 31 mA. Much lowerer!!

I have the bias mod, and I really want to install it, but I'd like to know who also has experienced this, and how (in what mode) have you biassed your Stiletto, and how hot is it set ?

When I switch to tube rectification, It even gets lower --> about 18 mA.

Ps: I am for sure I measured it the right, because I've emaild John Mansfield himself, showing a photo from my amp hooked up to the bias probe etc. I've connected everything like John / the manual said.

The bias difference between clean and overdriven sounds is huge as you see.

Hope you can help me!! Thanks in advance!
Stiletto ACE, TA-15

splatter
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Re: Lonestar bias mod

Post by splatter » Wed Sep 29, 2010 9:05 pm

alie123 wrote:Hi Lonestar fans, I have a question about the Bias mod, hope you can help me ..

I also have the Mansfield bias mod, (for my Stiletto ACE) I have some strange things. I am curious what you guys have experienced when installing the bias mod.

I have the mod not yet installed, because first before installing the mod, I was measuring with the Mansfield bias probe how 'cold' my amp was. What I found out was weird.

Clean modes (fat clean, tite clean) are stock biassed much higher then the overdrive modes, so In what mode have you set your amp when biassing with the Mansfield bias mod? (I don't want to blow my amp)

For example: with fat clean & tite clean I measure about 38 to 42 mA (depending on what tubes I installed)
and when I switch to channel 2, I measure about 30 to 31 mA. Much lowerer!!

I have the bias mod, and I really want to install it, but I'd like to know who also has experienced this, and how (in what mode) have you biassed your Stiletto, and how hot is it set ?

When I switch to tube rectification, It even gets lower --> about 18 mA.

Ps: I am for sure I measured it the right, because I've emaild John Mansfield himself, showing a photo from my amp hooked up to the bias probe etc. I've connected everything like John / the manual said.

The bias difference between clean and overdriven sounds is huge as you see.

Hope you can help me!! Thanks in advance!
Hey Al
I never heard back from you so I assume everything worked out ok ?

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