Harpin.J
22 posts
Dec 18, 2015
7:23 PM
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I'd like to open by saying I don't wish to look a gift horse in the mouth, but...
My brother-in-law gave me an interesting specimen as a gift: a re-issue '59 Bassman. I was gobsmacked. Seriously, I was taken aback...
Until he told me the details:"It doesn't really work." Then he said that he has modded this particular Bassman with a variable bias set-up, using a method he found on the internet. He put in two new Tung-Sol 6L6GCs in, thinking that might help. And, because a resistor smoked out, he put a couple of ceramic power resistors in their place on the power tubes - or something like that.
Well, it turned out he was right. It doesn't work. It starts out with promise and quickly diminishes into nothingness.
He had to show it off (I guess), so he turned it on and cranked it up.
I probably should have opened the back up and looked around before just firing it up and going to town...nevertheless...
Being that I am not that familiar with PC boards, my questions are: should I just say, "Heck with it." and sell it, or, should I, 1) spend the money and re-tube it hoping for the best; or, 2) build a point-to-point or turret board set-up to replace the PC board?
It does have three of the four blue-frame Al-Ni-Cos...
I'm not even sure that an old=school 5F6-A layout would work with the reissue stuff.
Thanks for your thoughts.
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Bass410man
55 posts
Dec 18, 2015
7:50 PM
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If the amp was free, than I would take it to a good amp tech and have it fixed. Even if it cost you 3 or 4 bills, you still have a good amp cheap.
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SuperBee
3096 posts
Dec 18, 2015
7:54 PM
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you should sell it to me real cheap and save yourself a big headache.
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Barley Nectar
984 posts
Dec 18, 2015
9:27 PM
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Yep, probably not much wrong with it. Eyelet board is no better then PCB sound wise. If you can follow a schematic you can figure that board out. It's not rocket science. Anyhoo, get it fixed and play the crap out of it! Yea baby...BN
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SuperBee
3101 posts
Dec 19, 2015
1:57 AM
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Apparently my fatuous remark was considered too spammy...it'll come back and then you can see how obvious I am...but I agree you should get a tech to fix it. That's what I'd do...and I'm envious...anyone want to give me a broken down bassman, I'm in the business of accepting.
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marine1896
539 posts
Dec 19, 2015
2:23 AM
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Oh man, keep that baby for sure! And I'm also sure Barley Nectar knows more about amps than me but years ago I knew a guy who had a early 90's Bassman RI which I played through when it had a PCB and he upgraded it with a Hoffman PTP and it was definitely a (to my ears) warmer better sounding amp afterwards, but he also loaded it with a genuine NOS Mullard valve rectifier, NOS matching tung sol power tubes and NOS 1950/60's green/yellow Sylvania pre amps!
Forgot but should add that particular amp was owned and gigged a lot by a guitarist in a psychobilly band for several years so however subjective, those speakers were well and truly broke in.
Yep get it to a good amp tech!
And your brother-in-law is a great brother-in-law!;-)
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"Those British boys want to play the blues real bad, and they do"
Last Edited by marine1896 on Dec 19, 2015 2:52 AM
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5F6H
1894 posts
Dec 19, 2015
3:00 AM
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Take it to a tech, it's had a noted failure, so the first thing to check is that the bias circuit is working correctly, ask the tech to rebias to ten to fifteen milliamps per tube. We don't know how much the power tubes have suffered, so replace them, no need to go mad, Sovtek 5881WXT are cheap & more than adequate.
The amp certainly be rewired with an eyelet board (the audio circuit in the reissue is the same as the late 50's originals), but this will be expensive ($/£400-500), trying to get it done cheaply can be a false economy.
If you get this amp sorted, there's very little that will best it.
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www.myspace.com/markburness
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jbone
2100 posts
Dec 19, 2015
9:40 AM
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About 10 years ago I got with Steve Clark of Sligo Amps and he built me a replica '59 Bassman. It cost pretty good but he was noted at the time for great Fender circuits and had a very good cab builder, so I took the plunge.
It was a great amp, P2P wired and all the best components Steve could find. Mix of speakers for low and high end breakup. Pretty much tailored for harp. I did one pre amp tube swap, a 12au7 in P3, and I j7umpered the clean and hot channels. It sounded fantastic and gave me a sense of power that I had to be careful to use responsibly! I kept it for about 4 years but my lifestyle and my back just were not conducive to lugging it around. I also took a lot of shit at jams for blowing up the guitars and keys. 40 watts and a good mic will do that. I dug it though! I sort of got banned from a jam unless I used their Blues Junior rig.
So the amp sounded absolutely great. Folks I gigged with begged me to unplug 2 speakers to cut volume in medium rooms and I did. Still plenty loud. But I was not gigging enough to make it worth keeping so I sold it off for 2/3 of cost and got a fishing boat.
There are times I'd like to still have it. I think every harp guy who wants to play blues or funk or jazz should at least get to blow through a 4x10 harp friendly rig.
If My bro in law gave me a gift like that I'd get it repaired, make sure it had a mod or two for a hi z harp mic, and blow with it for a while, just for the experience. Then If need be I'd sell it off and get my b in law a nice present.
I know there are plenty of reissue Bassmans out there having harp blown through them. I bet it would be a pretty easy fix.
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dougharps
1084 posts
Dec 19, 2015
10:25 AM
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I hear you about your back and a 4x10" amp!
I don't use more than a pair of 10"s or a 10" and a 12" with one of my vintage PA heads, and usually just a 10" OR a 12" depending on the room! I just don't play many rooms that need more than that, and it is a pain to haul a big amp, even though they are great when you use them.
Deak's reissue Bassman is fantastic to play through. I helped lug it at SPAH a couple years back. Ouch!
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Doug S.
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jbone
2102 posts
Dec 19, 2015
11:36 AM
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I got to blow one through Deak's amp in Cdale several years ago. It was truly a sweet sound.
I work in a duo mostly these days and we either use 13w Silvertone 1482's or 5w Fender Vibro Champs. Our p.a. weights 27 lbs without stands etc. I am about as happy at the farmers market or a storefront doing all acoustic too.
At age 60, with plenty of back issues, light is the way to go.
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http://www.reverbnation.com/jawboneandjolene
https://www.facebook.com/profile.php?id=100000386839482
https://www.youtube.com/watch?v=qbTwvU-EN1Q
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Joe_L
2644 posts
Dec 19, 2015
4:51 PM
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Throw it in the garbage!
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The Blues Photo Gallery
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6SN7
618 posts
Dec 19, 2015
6:04 PM
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Excellent! Get it fixed right and enjoy it!
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Harpin.J
23 posts
Dec 19, 2015
6:45 PM
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@Supe: Hilarious!
@Joe_L: Good stuff, but it begs the question: if a Bassman falls in the trash and you don't know where I live, will it ever make a sound?
Thanks for the input fellas. I think I am going to take it to a tech. I don't know why. I absolutely love playing harp and I play at home. I also find great joy in building smaller wattage tube amps. But, I don't play out - I suffer far too much from a paralyzing condition of stage fright. I really have no need for a Bassman. Nevertheless, I think this is my BIL's way of saying, "Get out there." He thinks I should, yet, I know I am nowhere near the level of ability that oozes from this board. To wit: I have no idea about band/jam etiquette (I know enough of the basics: don't play over the vocals; don't play too much; etc.); I've no ideas as to how to engage the sound man; how to call the style I want to the band; etc. The list goes on....
Anyway, after finally getting it home today, I rather haltingly and very apprehensively assessed the situation. From what I gather, my BIL bought the amp (via eBay) from Studio Instrument Rentals located somewhere by the Lincoln Tunnel in NYC. It has some stenciled numbering and lettering spray painted on the tweed. There are small swatches of some sort of weird green mold growing on the tweed (that I have since wiped off using an old dish towel and a small amount of bleach). I have yet to examine the speaker cones. I hope there are no mold issues there, but I'm not holding my breath.
I then took the back panel off. To my surprise it wasn't as bad as I thought. Yeah, there were some odd soldering joints, but overall, it seems salvageable from a technical point of view.
So, off to the tech it goes. I hope he won't steer me wrong...
Many thanks!
HJS
Last Edited by Harpin.J on Dec 19, 2015 6:52 PM
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Barley Nectar
989 posts
Dec 19, 2015
7:17 PM
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There ya go. Your speakers are probably mold free, they seem to resist mold somehow.
Mine had a little paint on it when I bought it from Joe Walsh's buddy. No it was not Joe's amp. Here's a before/after shot. My '94 Bassman is good electrically cuzz the seller is a good tech. All I did was put in a 5U4 rectifier. This dropped the voltages to match the original 59 schmo. Also put a 12AY7 in V1. Killer harp amp!!
Last Edited by Barley Nectar on Dec 20, 2015 7:21 AM
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Barley Nectar
990 posts
Dec 20, 2015
7:08 AM
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If you are going to put lower gain tubes in the preamp there are a few R's that need beefed up. I think they are the plate load resistors on the preamp tube sockets. These get the same value but increase to 1W size or more. I run 12AY7 in V1 and the rest are AX, just like the origional '59. Here is a good thread on the Bassman, you might have your tech read this. http://www.modernbluesharmonica.com/board/board_topic/5560960/923654.htm
As for stage fright, I get that when I try to sing. I think the key is to look fear in the face and just do it! Get with some people who will encourage you and work your way out of that fear. If someone gave you a Bassman for insperation, you are probably a way better player then you think!. Do it man!!!
Last Edited by Barley Nectar on Dec 20, 2015 7:35 AM
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jbone
2105 posts
Dec 20, 2015
7:23 AM
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Excellent insight Barley!
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https://www.youtube.com/watch?v=qbTwvU-EN1Q
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marine1896
544 posts
Dec 20, 2015
7:27 AM
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@Barley Nectar ; Nice looking amp I like the contrast.
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"Those British boys want to play the blues real bad, and they do"
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SuperBee
3106 posts
Dec 20, 2015
1:23 PM
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I think the plate resistors on the PI tube are most at risk from tube subs.
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Bass410man
56 posts
Dec 20, 2015
2:16 PM
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These are the resistors, and the one's you need.
• R-28 position on the PC board = 1 Watt, 82K www.Mouser.com
• R-29 position on the PC board = 1 Watt 100K www.Mouser.com
• “Carbon Comp” would be a good choice of the common three options
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Harpin.J
24 posts
Dec 20, 2015
5:49 PM
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Dang Barley, that amp is beautiful! Did you completely redo the tweed or use something to remove the spary paint? And thank you so much for the words of wisdom; both the technical and the inspirational. The jam I would attend is pretty loud and frequented by many fine blues musicians. Hence, my main fear factor: me going up there, making a damn fool of myself in front of these guys and being asked to never return - because harmonica players aren't really musicians anyway (although I know they are); I helped prove it. And I end up sullying the reputation of any and all future harp players at the jam. I know it's not rational, but...
In fact, I have only seen one harp player in the last 4 or 5 visits to the jam: Juke Joint Johnny (he was mentioned on this board by Adam himself).
Regardless, I will show the tech I'm going to the links and info provided in this posting and roll the dice. I've never been to the guy before so I'll have to be mindful of that; some people's egos might not be open to alternative suggestions.
This board is awesome!
Thanks again all!
HJS
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jbone
2106 posts
Dec 20, 2015
8:39 PM
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""me going up there, making a damn fool of myself in front of these guys and being asked to never return - because harmonica players aren't really musicians anyway (although I know they are)""
Hey man you hold that thought right there and be prepared to prove it. You will do fine. The guys who give harp a bad name are the ones who bluff their way in and become total asses. Just don't be that guy! I began going to jams way before I was "ready". I got "found out". But those guys had compassion and actually helped me along as best they could. If you do what you know with conviction and have good stage manners and presence you will have a great experience.
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http://www.reverbnation.com/jawboneandjolene
https://www.facebook.com/profile.php?id=100000386839482
https://www.youtube.com/watch?v=qbTwvU-EN1Q
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Barley Nectar
991 posts
Dec 21, 2015
6:56 AM
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Here ya go Harpin J, this is how I did the amp. To be honest, this came out way beyond my wildest expectations...
http://www.modernbluesharmonica.com/board/board_topic/5560960/5468508.htm
Last Edited by Barley Nectar on Dec 21, 2015 6:58 AM
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marine1896
548 posts
Dec 21, 2015
7:56 AM
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Barley Nectar, did you ever make the connection with your amp and Robert Lockwood Jr?
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"Those British boys want to play the blues real bad, and they do"
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Barley Nectar
992 posts
Dec 21, 2015
11:21 AM
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Not really, the seller is a tech who basically flipped the amp. He told me of the original owner who painted his initials on the amp and played with Lockwood. I was hoping some Cleveland cat would recognize the amp.
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5F6H
1895 posts
Dec 22, 2015
11:45 PM
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@Superbee "I think the plate resistors on the PI tube are most at risk from tube subs." These fail from time to time, but also R14 (feeds V2). This is the one I have had to replace most often.
The screen grid resistors (R32 & R33) are also prone to failure (on any of the RIs), if this has happened, tacking new ones to the old resistor legs may not solve the issue as the old legs can break free of the board & make the volume level intermittent, best to hard wire new resistors fed by the screen supply, directly to the tube sockets. I'd use 3W to 5W here.
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www.myspace.com/markburness
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Barley Nectar
994 posts
Dec 23, 2015
6:58 AM
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Thanks for the clarification mate. I gota get in mine one of these days and do the updates. Merry Christmas Mark...Goose
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5F6H
1896 posts
Dec 23, 2015
5:08 PM
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Cheers Goose, and to you!
Merry Christmas everyone.
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www.myspace.com/markburness
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