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jwh posted:lots of words Most amps I can think of, I can go on YouTube and watch someone, a hobbyist or a real tech, showing off the inside of the amp assembly and demonstrating this basic task of maintaining the tube amp. You have no idea how many threads and message board in corners all over the internet where people were talking about this, and they were all having discussions like this one. Someone like you would come in and say, "The amp is 'self-biasing." Then someone else would say they saw major voltage differences when they put in the TAD/GE/etc. new or NOS 12BH7 in the amp and they were concerned. There were sightings of burnt-up resistors and again, in one case, a guy had to drill holes into his PCB to remount components because the heat had made the PCB itself conductive. Man, I wish I could fully convey to you just how much fun I had playing this little guy yesterday. The one I bought is shipping today! (woo!) I take it with a grain of salt online because of course there's gonna be fud out there. And to be fair it's not like I'm throwing a ton of money at it. It looks to be in great shape, seller assures "no issues" so I'll hold them to that, and the whole expense is $300. I never learned the amp circuits per se but I built and worked on home-built transformer test-rigs where everything was exposed and would easily kill you. In the assembly room I was the only builder allowed to operate it. I build amplifier assemblies in their hundreds. I recently performed some hairy mods to my Blues Jr. I'm capable of working around and discharging caps. This 12BH7 is throwing me for a loop because it feels like common sense to re-tube an amp when you buy it, but a lot of people are reporting (and you're right, they could be mistaken) that this "self-biasing" amp needs to have those two trim-pots adjusted for each new 12BH7 you put in it. I'm not so sure I'm quite so ready to write those folks off. Many of them were being told by Blackstar to work directly off the manufacturers' tube data sheets and they, unlike myself, know their way around a schematic and managed to get hold of them (as did I). Would you be willing to let me message you before I make any changes, and give me a little direction to help me re-tube the little guy? No liability? The Muppets On PCP posted:and with that the entire guitarist message board community disappears in a puff of green smoke P.S. - Something else shipped today: a brand new Dunlop EVH phase 90 with power supply and patch cable. Gonna really get my Van Halen 1 on!
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Aug 14, 2017 23:33
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Dr. Faustus posted:of course there's gonna be fud out there. Hey, you're right! 
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Aug 15, 2017 04:41
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Yeah, that's what happens when you venture in TDPRI territory. I've seen things, but I try to forget them.
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Aug 15, 2017 07:45
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Yeah Mr Faustus I wouldn't worry too much about the poopooing on the net, like I said, it's not a marshall, fender, vintage or niche amp so of course most of the internet guitar-o-sphere doesn't think they're worth while. In my experience they take pedals really well, too. I look forward to reading about your experiences with changing the tubes etc. I think the power section sounds pretty drat good to be honest, but I wouldn't mind cleaning up the preamp a bit.
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Aug 15, 2017 07:58
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field balm posted:Yeah Mr Faustus I wouldn't worry too much about the poopooing on the net, like I said, it's not a marshall, fender, vintage or niche amp so of course most of the internet guitar-o-sphere doesn't think they're worth while. Thanks very much. Every purchase like this is a leap of faith. The amp I played in the store sounded fantastic so I am hoping to come back and tell you how great my new used amp is. It'll be next Sunday at the earliest before I can record but I'll try to provide sound clips. As far as the tubes go, I'll take my time to learn a lot more about the power section and tube replacement. The amp I played cleaned up to a brilliant shiny clean sound without switching channels to the clean channel, just by rolling off the volume on my JEM. The clean channel sounded so good. I can't wait to put all the parts together and play them. I won't keep you waiting, I'll mic it up and post some clips if the amp itself is fine. Thanks for the reassurance that it takes pedals well. I intend to put all modulation/delay effects in the loop. That means I need to buy a reverb pedal eventually.
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Aug 15, 2017 08:47
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Dr. Faustus posted:The amp I played in the store sounded fantastic This is all most of us ever need to worry about in regards to "is this piece of gear a good purchase" questions.
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Aug 15, 2017 16:22
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Dr. Faustus posted:This 12BH7 is throwing me for a loop because it feels like common sense to re-tube an amp when you buy it, but a lot of people are reporting (and you're right, they could be mistaken) that this "self-biasing" amp needs to have those two trim-pots adjusted for each new 12BH7 you put in it. When you get the amp, see if you can't find these trim pots for me, because I'm not seeing them on the schematic...
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Aug 15, 2017 16:38
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jwh posted:When you get the amp, see if you can't find these trim pots for me, because I'm not seeing them on the schematic... poo poo did I miss the schematic? I barely could penetrate Faustus' wall of text mostly because I have the attention span of a goldfish. Edit: Faustus, luv u, Boo. :bigtran: Dang It Bhabhi! fucked around with this message at 20:07 on Aug 15, 2017 |
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Aug 15, 2017 19:55
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jwh posted:When you get the amp, see if you can't find these trim pots for me, because I'm not seeing them on the schematic... Owners said there is a pot for "bias" and one for "balance," apparently to equalize the work of each triode on the tube. I saw no pictures. Here's something someone managed to pry out of a Blackstar tech. I'm not entirely sure what it means yet because I need to find "4." quote:Ok. Got some help from Blackstar. Measure voltage across 4,7ohm resistor on cathode. Adjust to mV reading of 46mV. Adjust balance pot for least amount of hum from speaker. Dang It Bhabhi! posted:poo poo did I miss the schematic? I barely could penetrate Faustus' wall of text mostly because I have the attention span of a goldfish.
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Aug 15, 2017 22:22
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We talked about those Vox amps with the Korg NuTube in them? The MV50. I am intrigued!!
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Aug 16, 2017 04:34
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Dr. Faustus posted:I will, but I don't know anything about the assembly yet. Ah, found it. It's PR1 and PR2 variable potentiometers in the back PCB schematic. PR1 controls the overall negative voltage that's sent from the -12vdc rail to the 12bh7 grids. PR2 controls the balance between each side of the 12bh7. This is a combination of the two approaches people have taken variously, in the past. Good for them for giving you such fine-grained control over how the output tube is set up. The amp has two secondaries on the power transformer, one to derive the HT voltage for the power tube plates, and another, smaller winding for rectifying a +12 and -12 volt supply. That's what's going on here. Fun fact: the +12 volt supply also turns on a LED and through the help of a dropping resistor, providers tube filament heater current. http://music-electronics-forum.com/attachments/7090d1259344094-ht-5-power-amp-supply.gif
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Aug 16, 2017 19:57
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I hope you can help me retube the amp. If not, it's ok. Even the local tech my friends use said Blackstar won't tell him poo poo. Par for the course, I guess. I got my new amp, and here is the cross-post from the Post Your Next/Newest Gear thread: quote:I got my used Blackstar HT-5. I am extremely loving thrilled to report that it has all the mojo the one I played last Sunday at the music store has, while looking a little sharper and being $150 cheaper. I hope the Blues Jr. can find a happy medium. I put so much careful work into that little guy, it hurts my pride that it's not working right. I'll have news on THAT in about a month. Dr. Faustus fucked around with this message at 05:36 on Aug 18, 2017 |
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Aug 18, 2017 05:12
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Sure, but if it sounds great, just enjoy it, instead of mucking with it. Also if you like the OCD, check out the OCDv2 that Mike just came out with last month. It's probably the single best sounding dirt pedal I've ever heard.
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Aug 18, 2017 16:57
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jwh posted:Sure, but if it sounds great, just enjoy it, instead of mucking with it. I have a question that maybe belongs in another thread: Right now I have the modulation/delay effects in the effects loop and it's wonderful. I'm currently using the -10dB setting out of caution. Is there any reason I shouldn't switch over to eh +4dB setting for the loop? Will it hurt my pedals or help them stand out more? Anyone?
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Aug 19, 2017 02:40
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In the same way that plugging into the high sensitivity input on the amp won't blow it up, no, you're not going to hurt anything. If they can't handle the extra signal, they'll distort. I've had some pedals do this. They survived. Your pedals may sound better, or worse, or about the same.
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Aug 19, 2017 20:17
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Yep, it'll just clip no biggie. The FX loop is part of the preamp, basically, but you're putting the signal in between the preamp and power sections. Overdriving the power section may not even sound bad. The Earthquaker Acapulco Gold and DAM Sonic Titan actually work by clipping the poo poo out of a class AB amplifier IC.
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Aug 19, 2017 22:59
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Good to know, I'll flip the switch and see how it sounds. Depending on your definition of "long," I finished a couple nice 15' instrument cables for the effects send/return so I have plenty of room to move them around. In front of the amp I've got I think an 18' Dr. Faustus fucked around with this message at 00:27 on Aug 20, 2017 |
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Aug 20, 2017 00:15
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If your pedals are capable of handling line level input and you're running long cables then running at +4 will potentially result in less noise. So it's worth a try at least.
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Aug 20, 2017 00:19
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Carrying this over from the guitar thread a week or so ago. I want an attenuator for my 15 watt OR15. I want it to... attenuate and also work for plugging my amp directly into my Scarlett 2i4 for recording via IRs assuming that's the best way to deal with the lack of a cab in the setup. What are the favorites without going crazy and dumping a ton of money?
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Aug 20, 2017 00:42
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Weber mini mass
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Aug 20, 2017 00:50
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Bill Posters posted:Weber mini mass
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Aug 20, 2017 01:44
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Some dude may have fried the power amp IC in his Boss Katana. So he takes a picture of it to figure out which IC it is. It is a Boss "IC700" lol wtf. Guess replacement parts won't be easy to come by for a while. My Orange Micro Terror used an off-the-shelf chip like god intended.
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Aug 22, 2017 02:42
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Katana-100 vs THR10 for livingroom? I'm thinking the latter for my Metallica, Motley Crue, Mastodon, Morbid Angel, Motorhead sounds. Thoughts?
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Aug 22, 2017 19:54
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I can nail all of those extremely well with my THR10X.
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Aug 22, 2017 20:25
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I hasten to add that there's a pub with live music down the road from my new house that hosts rock/metal cover bands, which is why I thought KTN-100 might be useful as dual purpose.Kilometers Davis posted:I can nail all of those extremely well with my THR10X. So why the gently caress does the regular one still exist? For what purpose? (ps. I don't give a shiny bag of poo poo about the acoustic amp model, but have something I can do with bass and clean guitar would be helpful when "recording" aka that thing I always tell myself I'm buying all this poo poo for) pps. I really hate modern heavy metal
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Aug 22, 2017 20:42
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Honestly I'm not sure. The X covers all the mid to high gain really well and the clean + bass handle whatever else I throw at it. I compared them all and I didn't see the point in grabbing something other than the X unless you absolutely hate gain tones. I don't know anything about them but the Katana definitely sounds like a better option for playing out. The recording comment hits way too close to home 
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Aug 22, 2017 21:01
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Everyone seems to be fellating the katana hard and its definitely more capable for playing out.
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Aug 22, 2017 21:04
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Hmm... so THR10/10x is definitely a "stick on the shelf and not take up much space" thing. Honestly probably a good first port of call. This dude seems to rip through all the songs I enjoy with relative ease on a THR10x so I'm sold: https://www.youtube.com/watch?v=fJ1KgBUsdSg Southern Heel fucked around with this message at 22:55 on Aug 22, 2017 |
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Aug 22, 2017 22:13
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If you haven't watched the Satchel demo of the THR10X look it up. Whether you find him hilarious or punchable it's a very honest demo of the amp's abilities and he plays a lot of the kind of stuff you seem to be into. Also the Mattias IA Eklundh play through is the reason I decided it was worth owning. That guy could sell anything though. Kilometers Davis fucked around with this message at 22:36 on Aug 22, 2017 |
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Aug 22, 2017 22:33
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Boss Katana is the king of bang for the buck right now, imo.
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Aug 22, 2017 22:44
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Dang It Bhabhi! posted:Boss Katana is the king of bang for the buck right now, imo. Yes but I'll have to find a cupboard for it, make a new pine cabinet or whatever for it, for it to be in my livingroom. I'm not neccesarily poo-poo'ing the idea. Infact I think I will go to a shop on Thursday to A/B both. Ultimately I just need the same sound my Friedman has, but in a smaller box that I can put headphones on if required. 'just'.
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Aug 22, 2017 22:57
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I tried all three variants of the THR-10 and I chose the original because I felt it had more useable tones than the C or X.
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Aug 23, 2017 00:11
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My one mess with the 80s/90s park cabinets? I have an eye on a 412 cheap plan on stripping the already busted Tolex and sand/stain it. Heard there is substantial wood underneath it. How are the speakers?
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Aug 23, 2017 02:02
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I tried the THR 10 x in a music store and I was really underwhelmed by the volume. It was a fairly big room but very quiet.
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Aug 23, 2017 02:29
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Isn't it a bedroom amp by design? Seems like low volume is the point.
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Aug 23, 2017 02:37
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I get that but it was pretty wimpy even by that standard. Just my opinion. It really put me off of them. fake edit: it was a big room too. I just wanted to mention the one piece of gear I have actually played.
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Aug 23, 2017 02:51
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My Dad and I don't get along well. That said, he is, undeniably, a bad rear end (and no, that's not why we don't get along.) Me doing the Blues Jr. mods got him into doing his own Blues Jr. mods, and then he hatched a plan, that he only revealed to me after it was nearly complete: He was going to build his own Fender Twin Reverb. You see, he graduated High School in 1957. He says his favorite electric player is Eric Clapton. (I've never heard him listen to Clapton, but whatever.) He tells me Fender is going to reissue a certain model of Twin Reverb, one that he associates with Clapton and his days in Cream. I don't know how accurate any of this is, ok? The amp is the 5E8-A '57 Twin Reverb (same year as his high school class). So he decided to buy a cabinet, and a chassis, and a pre-drilled fiberglass board, and all the components to recreate the thing from a schematic. He's an Electrical Engineer (of sorts) so he can do poo poo like that. He told me about sourcing hundreds of parts. About testing capacitance on various brands of caps and rejecting some for others that matched his tolerances better. And the thing is, he loving did it. And the other thing is, I'm sure he aced it. He never does anything by half-measures. A lot of this stuff was sourced through MojoTone in NC, btw. I spoke to him on Sunday and he said all that was left was to install the power cable and re-test all his connections, then install the tubes. I guess he finished. He had to mount the chassis in the cab up-side down because doing it upright was a two-man job and so he was going to make it easy on himself, which explains the upside-down pictures. I told him it was too bad he bought two brand new Jensen C12Ns because I just took a brand new one out of a Blues Jr. and would have happily donated it to his dream amp. I'm not going to lie, I am blown away that he did this. I will meet it at Thanksgiving, and he will have to leave me alone with it because I will play it much louder than he can tolerate. The pictures (Taken with Mom's phone camera, expecting better pictures soon): Circuit: Left to right:       Sorry about the picture quality. This is what I would call serious Amplifier Worship. He wasn't willing to pay Fender for a re-issue '57 5E8-A, but he'd sure a gently caress build one.
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Aug 23, 2017 03:51
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...and the pitch! posted:I get that but it was pretty wimpy even by that standard. Just my opinion. It really put me off of them. I'm not trying to say you're wrong but are you sure it was dialed in with both volumes up and working right? It gets super loud. Like way louder than anyone would need short of playing with a band.
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Aug 23, 2017 03:55
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Kilometers Davis posted:I'm not trying to say you're wrong but are you sure it was dialed in with both volumes up and working right? It gets super loud. Like way louder than anyone would need short of playing with a band. I feel like I tried to crank it but I might have hosed it up. Maybe it was the room.
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Aug 23, 2017 03:59
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A lot of people including me at first don't realize you have to set the the preamp and master to taste and then use the volume on the right side (guitar vol I think) to get it as loud as you want. I'm admitted not a cranked amp kind of player but when it's positioned around head level like it's supposed to be it puts out a very loud full sound. Who knows though, might just be different perceptions.
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Aug 23, 2017 04:02
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