Hey all. A while ago, I bought a Blues Jr. It's my first small tube amp (I have a Marshall JCM2000 DSL100), and like most DIYers, I want to mod it.
I ordered the basic kit from Bill M back at Thanksgiving, and have heard NOTHING. I've sent numerous emails, and keep an eye on his website. The problem is, the basic mod doesn't appear to be documented.
Even if the bass and mids are set to 0, and treble turned up, it's still waaaaay too bassy/muddy to me. Everyone talks about too much 'sparkle,' and I feel as though I get ZERO.
Anyone have any recommendations aside from "burn it, sell it, or whatever." I want to make this small amp great, just like the ones I've heard at my friends' houses.
TIA,
Kyle
Did you buy it new? If it's that muddy maybe there's a problem with it. Have you tried other Blues Juniors to compare the tone?
You could always try different tubes or a different speaker.
It took him a long time to ship my Blues Jr. mod kit. Like 4 months, never responded to follow up. Another guy at work modded his and said he had the same experience.
Quote from: Matmosphere on March 17, 2016, 06:14:29 PM
Did you buy it new? If it's that muddy maybe there's a problem with it. Have you tried other Blues Juniors to compare the tone?
You could always try different tubes or a different speaker.
Nah, I bought it used. I have played my friend's. It's gorgeous and the reason I bought mine. I did put in new tubes, and that seemed to have little effect. I was hoping to mod the PCB before a new speaker, but I'm tempted to try a new speaker ASAP.
Quote from: EBRAddict on March 17, 2016, 06:27:18 PM
It took him a long time to ship my Blues Jr. mod kit. Like 4 months, never responded to follow up. Another guy at work modded his and said he had the same experience.
Yeah, I'm trying to be gracious; I know he's been through a lot, and who knows what's going on now. But, man... it's just some caps and resistors. If it's going to take 4 - 6 months, just tell us what the mod is, and let us do it. I wish someone would disseminate the info provided in the purchased kit.
I know I've read a thread or two over at BYOC, maybe a year or two ago, that had a link and or documented on how you do the mods. Sems like a mod over there has done and or provided the link or something. You could try the search button over there.
I suppose you're aware of Bill's health issues. That's not an excuse for poor business practices, but just an acknowledgment of reality.
Regardless, the easiest mod is the TwinStack mod described on his site here (http://billmaudio.com/wp/?page_id=58). With the stock tonestack, you can never turn the bass off as the mid pot, even at full ccw, keeps plenty of bass intact. By adding the jumper, you convert the tonestack into a more typical BF style, and when you turn the bass full ccw and mids down, the bass is gone *poof*.
If you find, after the mod, the speaker is still too woolly, check out the WGS G12C or Eminence Legend 1275. Both very affordable.
Quote from: TNblueshawk on March 17, 2016, 06:51:57 PM
I know I've read a thread or two over at BYOC, maybe a year or two ago, that had a link and or documented on how you do the mods. Sems like a mod over there has done and or provided the link or something. You could try the search button over there.
I'll do some searching there; appreciate it!
Quote from: oldhousescott on March 17, 2016, 06:55:04 PM
I suppose you're aware of Bill's health issues. That's not an excuse for poor business practices, but just an acknowledgment of reality.
Regardless, the easiest mod is the TwinStack mod described on his site here (http://billmaudio.com/wp/?page_id=58). With the stock tonestack, you can never turn the bass off as the mid pot, even at full ccw, keeps plenty of bass intact. By adding the jumper, you convert the tonestack into a more typical BF style, and when you turn the bass full ccw and mids down, the bass is gone *poof*.
If you find, after the mod, the speaker is still too woolly, check out the WGS G12C or Eminence Legend 1275. Both very affordable.
Yeah, I'm aware of his health issues, and that's why I try to afford grace. My mom recently died from pancreatic cancer, so I know what cancer does.
Your explanation of the TwinStack mod is the best I've heard. I didn't realize that, and definitely planned on doing it when I got the kit in. Now, I may just go ahead and do it.
Someone in my local music exchange group was selling a Red White and Blues speaker for $50. According to Bill M, that'll greatly help with the high end. I'm tempted.
Which version BJ is yours--the cream board or the old green board? I ordered and installed the green board kit on my old '96 BJ, as well as putting in a Switchcraft jack and swapping out the remaining 22uf power supply caps. I got fairly lucky on how quickly I got mine as it was before he got ill. The instructions were really good but some of the parts numbers may be different than what I have if you've got the cream board.
Besides the very useful Twin Stack mod (and the explanation of what it does provided above is dead-on), the mods basically increase the main 47uf power supply cap to 100uf (Bill provided a low ESR variety); bass cap is increased to 0.1uf, mid cap is dropped down to 0.015uf; the two main coupling caps are swapped out for Orange Drops of the same value as the original (0.1uf, I think). The addition of a bias trimmer is really the big one. All this adds up to make it sound like a really good Princeton reverb or something. If this makes sense, it has more bass on tap (and I have to actually dial it back a bit), but it sounds way clearer and punchier.
Let me know if you need any info from my set of instructions! :)
Quote from: Bret608 on March 17, 2016, 07:18:33 PM
Which version BJ is yours--the cream board or the old green board? I ordered and installed the green board kit on my old '96 BJ, as well as putting in a Switchcraft jack and swapping out the remaining 22uf power supply caps. I got fairly lucky on how quickly I got mine as it was before he got ill. The instructions were really good but some of the parts numbers may be different than what I have if you've got the cream board.
Besides the very useful Twin Stack mod (and the explanation of what it does provided above is dead-on), the mods basically increase the main 47uf power supply cap to 100uf (Bill provided a low ESR variety); bass cap is increased to 0.1uf, mid cap is dropped down to 0.015uf; the two main coupling caps are swapped out for Orange Drops of the same value as the original (0.1uf, I think). The addition of a bias trimmer is really the big one. All this adds up to make it sound like a really good Princeton reverb or something. If this makes sense, it has more bass on tap (and I have to actually dial it back a bit), but it sounds way clearer and punchier.
Let me know if you need any info from my set of instructions! :)
(http://uploads.tapatalk-cdn.com/20160317/1cc74a52f71c17b76128e0f5fece8bd7.jpg)(http://uploads.tapatalk-cdn.com/20160317/368d638ca6a47dbb782331d4933702b7.jpg)(http://uploads.tapatalk-cdn.com/20160317/239ebc60b0a5d293e189bb34a27c362a.jpg)
Sent from my SM-G920V using Tapatalk
Sorry, wanted to get the pics uploaded.
It's a Rev C green board. The tubes aren't even 3 months old. I want to fix the reverb issue with the green board, and I'm told the tank may have an issue. (I haven't investigated yet.)
I'd say if you got it used AND it sounds completely different from others you've used you need to make sure everything is right with the amp before you mess with modding it. If there's something wrong with it then it's probably not going to sound any better after the mod and it might be harder to figure out how to fix it.
The Billm mods were great for my Blues Jr. Their transformer was also a big improvement for my Princeton Reverb reissue. That said, your experience is the same as mine re: customer service: looooooonnnnggg wait times for product and little or no communication except when they need to reach you. The exception seems to be if you have a tech problem while making mods you've purchased. They're pretty quick to respond on that (at least in my experience). Per other posts, I understand the delays are due at least in part to Billm's health issues ... which I'd wish on no one. I think his son Andrew now does most work, including packing/shipping parts. So ... I guess it's sort of buyer beware on the timing front for what many people like in terms of outcome. There are other options (e.g. http://www.fromelelectronics.com/collections/amp-mod-kits (http://www.fromelelectronics.com/collections/amp-mod-kits)), but I have no experience with anyone but Billm and my local amp tech. I dunnno if all that's helpful or not ... :-\
Quote from: daleykd on March 17, 2016, 06:50:35 PM
I wish someone would disseminate the info provided in the purchased kit.
After all this time, I can't believe nobody has posted the information.
I'll have to dig thru my stuff and see if I still have the instructions. I dont remember what mods I did but here is a pic of mine - obvious stuff like power filter caps, a couple orange drops, and the added trim pot for biasing... that was the hardest part
I mod tons of these for people. IMO here is order of importance:
1: bias, need to cool it down as the EL84s are absolutely cooking and damage the pcb.
2. speaker change will make the biggest difference in tone for you (WGS G12C good choice)
3. parallel another 47uf reservoir cap on, it helps the bass when you turn it up
4. Amp should be sounding way better. If still not pleased then do the tone cap mods
I've done a bunch of BillM mods for buddies. I'm not really sure that it's in anyone's best interest to let the cat out of the bag in terms of just giving away the mods. I agree though that the ordering process is brutal and that goes back to when Bill was still healthy. That said, yes, if the amp is that bottom heavy in terms of tone there's definitely something going on. That's a real nice tube set and it should sound very bright. Most of the BillM stuff involves getting rid of the shrill top end and adding a bit of punch to the low end by stiffening up the power supply. I'd play thru another speaker to make sure that it's not a speaker problem first.
Quote from: daleykd on March 17, 2016, 06:50:35 PM
Nah, I bought it used. I have played my friend's. It's gorgeous and the reason I bought mine.
You still haven't clarified if you compared yours to another stock Blues Jr. and whether it sounded different. It's boxy sounding for sure but it shouldn't be as dark as you seem to be describing.
I can't even figure out HOW to order a billm mod kit. The web site is confusing. I would think the "mod kits and services" page would be it, but that page is password protected. WTF?
Quote from: culturejam on March 18, 2016, 12:18:14 AM
I can't even figure out HOW to order a billm mod kit. The web site is confusing. I would think the "mod kits and services" page would be it, but that page is password protected. WTF?
I think the store is still closed from January. The "News for January" says "The Billm Audio web store will not reopen until the current backlog of orders and amplifiers has been filled: I am loath to provide an estimate."
I reread my post and it sounded a little soap-box preachy. What's everyone's take on this? Is it fair game if you can't place an order now or what? Or is intellectual property still IP. Given the nature of our adventures here maybe I'm being too close minded?
Quote from: gordo on March 18, 2016, 02:11:07 AM
I reread my post and it sounded a little soap-box preachy. What's everyone's take on this? Is it fair game if you can't place an order now or what? Or is intellectual property still IP. Given the nature of our adventures here maybe I'm being too close minded?
I thought you were on the mark. Billm has put a lot of effort into learning and tweaking that amp and others, then putting kits together to make a business. Seems fair to give him his due by not sharing what he's asked folks not to. To me, at least, but I'm rife with contradictions so ... that's less than useful.
Quote from: gordo on March 18, 2016, 02:11:07 AM
I reread my post and it sounded a little soap-box preachy. What's everyone's take on this? Is it fair game if you can't place an order now or what? Or is intellectual property still IP. Given the nature of our adventures here maybe I'm being too close minded?
Good topic for a discussion. ;D
From a legal perspective (and midwayfair may have some better insights than me), I'm not sure how you can protect the concept of changing component values, replacing a transformer and speaker, and making other modifications to an electronic device. Certainly the document that contains this information can by copyrighted (and is automatically copyrighted upon creation, as is any document or photograph or drawing, etc). But I don't think there is anything specific in those mods that is "non-intuitive" and thus protectable.
Let's look at it another way. Suppose you decide you're not going to pay for the billm mods and you're going to experiment for yourself and find out what works best. You spend some time modding the amp and testing, making notes as you go. Then you decide to share your findings with world by publishing this information online. Turns out that most of what you discovered is exactly what's in the billm mods document. Are you violating his "intellectual property" by posting your findings? Is no one allowed to publicly discuss Blues Jr mods that are similar to billm's because now he owns the idea of modding a Blues Jr?
I think not.
Now, that's not to say that I per se advocate that someone should info-dump his mod documents on the web as a free-for-all. But I'll say that I am *stunned* that after all this time, not a single person has summarized the mods in their own language and posted it online somewhere. Stunned, I say.
I actually did find a run down of his mods on an ancient TGP or telecaster forum post (damned if I can find it now, though). I seem to remember him and Fromel discussing the merits of some of the mods. I ended up ordering his kit as the price didn't end up much worse than if I'd pieced it together myself. The documentation was helpful for sure. I agree with Pryde though about the order of priority. The tone cap mods might not be for everyone.
Great discussion, and I greatly appreciate it.
I think I am curious about finding the information online only because there's no guarantee that my money wasn't a waste. As someone who has an e-commerce site, I couldn't fathom finding it acceptable to sell a kit and not ship it for 6 months with no communication. And there's no way for me to ask for a refund.
I mainly wanted the kit for the bias information. I've had multiple people say "cool those tubes!" I also wanted the information on how to fix the reverb for the green boards. Heck, if it was a locked page that he gave you a key to when you paid him, I'd be happy with that!
At this point, if a trustworthy amp tech lived closer to me, I'd just take it to him. I just don't feel like driving an hour to get to one.
Quote from: Bret608 on March 18, 2016, 01:43:25 PM
I actually did find a run down of his mods on an ancient TGP or telecaster forum post (damned if I can find it now, though). I seem to remember him and Fromel discussing the merits of some of the mods. I ended up ordering his kit as the price didn't end up much worse than if I'd pieced it together myself. The documentation was helpful for sure. I agree with Pryde though about the order of priority. The tone cap mods might not be for everyone.
I read this at one point, too, so I know it's there. However, I couldn't FULLY decipher it.
Quote from: daleykd on March 18, 2016, 03:01:14 PM
I mainly wanted the kit for the bias information.
Buying a kit for that reason is ... well, don't do that. Learn how to bias the amp, and then bias it according to the tubes you actually have.
WATCH BOTH. Don't skip the first one.
And I'll also preliminarily say that running your tubes colder is not going to give you a clearer tone or better bandwidth.
Quote from: midwayfair on March 18, 2016, 06:19:30 PM
Quote from: daleykd on March 18, 2016, 03:01:14 PM
I mainly wanted the kit for the bias information.
Buying a kit for that reason is ... well, don't do that. Learn how to bias the amp, and then bias it according to the tubes you actually have.
WATCH BOTH. Don't skip the first one.
And I'll also preliminarily say that running your tubes colder is not going to give you a clearer tone or better bandwidth.
Fixed the YouTube links, because I'm interested to watch them.
MetroAmp's 50W Plexi kit build doc is worth reading for the bias section.
First, I learned something this week: if I turn all 3 of the tone knobs up to 12, it sounds much better.
I've done a lot of reading this last week on the mods (still no word from Bill or his son) and have a much better understanding. I've ordered parts from Mouser to replace the tone caps, coupling caps, and main 47uF.
The only thing I can't quite grasp is how he did the sparkle mod. Has someone done this before? It's an A500k push/pull pot, with (what looks like) a 3n3 cap on one of the switches. You pull out the voicing cap and replace one side with the wire. Problem is, I can't quite tell how everything is wired up on the pot.
Thanks for all of your help.
[I plan on taking my stock Blues Jr to my friend's house tonight and comparing it apples-to-apples with his stock Blues Jr.]
if you can bear with me I'll run them all down for you(at work at the moment). I just came across this thread and I've done mods to both green and cream boards. The ones I don't care about (like drilling the chassis to add stuff) aren't included but I've done the tone, twin stack, reverb, standby, 4/8/16 Hammond transformer, etc. And you can save a lot of money because most of billm's mod parts are available over at antique electronic supply if you know where to look for them.
obviously some of his pages give you a straight rundown and instructions with values of what to do like the following
http://billmaudio.com/wp/?page_id=58 - twinlike mid knob
http://billmaudio.com/wp/?page_id=34 - fixing green reverb
http://billmaudio.com/wp/?page_id=141 - cathode follower
Original Fender® Part Number 00373230000 - better reverb taper pot, better master volume taper as well both 50KB stock, changed to 50KA
Tube compliment for maximum clean headroom with cathode follower mod v1 12AY7, V2 12DW7, v3 12AT7
Hammond 1760F 4/8/16 output transformer for Blues Jr
Granted I'm not home to check my amp but I believe he swaps the 22n bass cap for 100n like the blackface twin. he also swaps the 22n mid cap for a 15n as well. If you wanted a true blackface twin tone section you'd need to change the taper of the bass pot to an audio taper and change the mid pot from 25K to 10KA and the mid cap to 47n.
Sparkle mod changes c35 on a green board (c9 on cream) from 1.5n to a variable from zero to 3n. zero would be series III value, 1.5n is stock series 1 or 2, 3n is darker than useable(imo). I waited on this mod to last and voiced it accordingly. I found stock on the series one and two to be darker than "the fender sound" I was looking for. Also consider removing and jumpering the 33n capacitor at C19 (c10 on cream board)
presence control changes negative feedback resistor r26 from 7K5 into a 10K pot.
Mod brand reverb tank https://www.tubesandmore.com/products/P-RMOD-8EB2C1B
btw the long decay version doesn't play well with the green board even after the mod
power stiffening mod - adds a second 47uf cap in parallel with the 47uf in the power supply
fixed bias mod - increase r31(r52 cream board) to 27K
off standby on switch - https://www.tubesandmore.com/products/P-H520
green board instructions
4 poles left to right, top to bottom numbered 1-4 (pole 1 oriented middle of switch body, left hand side when looking at switch)
pole one to black lead from S2A, pole two to CP12(remove existing lead at CP12), pole three to black power cord lead, pole four to lead that was at CP12
cream board instructions
same switch orientation and labeling as before
pole one to black power cord lead, pole two to CP11 (remove existing lead at CP11), pole three to black lead from S2A, pole four to lead that was at CP11
I will say the best modification for this amp is by far a new speaker and a larger cabinet or switching this to a head unit.
Quote from: thesmokingman on April 04, 2016, 01:21:31 PM
Granted I'm not home to check my amp but I believe he swaps the 22n bass cap for 100n like the blackface twin. I think he also swaps the 22n mid cap for a 47n as well.
You're right on the bass cap. Mid is changed to a 15n.
that would definitely get you more lows and low mids and should shift a now shallower notch upwards from the blackface twin tone stack. if you're keeping the stock cabinet and speaker, it would help it feel a little less "small" or "boxy"
Looks like you're making progress! Let me know if you want to do the bias mod also. My amp is a green board revision "B", so the resistor that gets swapped out for the trimmer is almost certainly the same part number as on your board. This involves drilling a couple of small holes in the vicinity for the trimmer legs, as well as scraping away some trace covering to make a new solder pad. It's easier than it sounds. The part where he explains how to bias is probably the most detailed of the whole set of instructions. But, he also put a video on YouTube that does the job nicely too.
Quote from: Bret608 on April 04, 2016, 08:09:42 PM
Looks like you're making progress! Let me know if you want to do the bias mod also. My amp is a green board revision "B", so the resistor that gets swapped out for the trimmer is almost certainly the same part number as on your board. This involves drilling a couple of small holes in the vicinity for the trimmer legs, as well as scraping away some trace covering to make a new solder pad. It's easier than it sounds. The part where he explains how to bias is probably the most detailed of the whole set of instructions. But, he also put a video on YouTube that does the job nicely too.
Thanks, man. I think I've got the resistor and capacitor numbers for my board. I'm definitely doing the bias mod (my parts should show up late this week, early next week; [Mouser shipping sucks, and I live less than 2 hrs away]).
On a side note, @midwayfair (Jon), I finally A/B'd my amp with my friend's last night. I have a green board, and I'm like 90% sure his is a cream board; both are stock. With a true apple-to-apples check, mine was DEFINITELY bass heavy and missing out on treble. He agreed (which makes me feel less crazy). When I turned up my treble and the bass/mid down a bit, we were closer to each other.
I have a good feeling about these mods.
I'm am pleased to report that it sounds amazing now! I have finished all the mods I wanted to do (maybe a new speaker some day in the future), but the thing has all the tone control I could ever want now.
Thanks for your help and education, gentlemen.
Glad to hear it worked out! I need to think about a speaker upgrade for mine too at some point.