Small Tube Amps Dilemma

Discussion in 'Glowing Bottle Tube Amp Forum' started by muptup, Dec 2, 2013.

  1. DaveKS

    DaveKS Friend of Leo's Ad Free Member

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    That's the way to go, play it for a month or 2, get speaker broke in then maybe roll speakers and tubes. So many people start rolling speakers when they haven't broke their original in. Enjoy.


     
  2. jefrs

    jefrs Doctor of Teleocity

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    PPIMV = Post PI Master Volume.

    PI being the Phase-Inverter that drives the output valves.

    This was Marshall MV effort originally, there being nowhere else to stick the MV

    The MV usually goes before the PI, the PJ hasn't got an MV.
    I mentioned this. I have two very similar WEM amps, one with the MV the other without. The MV version is usable at home, the other has to be reined in well below its sweet spot.

    I have added a pre-PI MV to my Epi Blues Custom 30 (BC30), which is yet another Bassman clone and it works well. I can use this 2x12 >>30W beast at home. This is the usual position for an MV and much simpler than the dual-gang control needed after the PI.
    The MV pre-PI replaces the lower fixed resistor of a voltage divider pair right before the PI. This is at the reverb return point on the BC30.

    I do not know the PJ circuit but suspect it is none too dissimilar to other Fender amps and the BJr in particular. Borrow the MV from the BJr circuit "Master" pot.
     
  3. colchar

    colchar Friend of Leo's

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    Personally, I would grab an amp with a master volume control or a built in attenuator/output control. Either that or get a bigger amp and just use pedals for dirt. I do that with my PRRI and can play late at night without disturbing anyone else in the house.
     
  4. wrathfuldeity

    wrathfuldeity Tele-Afflicted

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    idk about the feasibility but mod a fx loop and use a volume pedal....and you can put other useful things in the loop, e.g., eq, delay and etc.
     
  5. jefrs

    jefrs Doctor of Teleocity

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    Why buy a good amp and have to modify it rather than buy a good amp that does what you need?
    Note that "what you need", buy with your head not your heart and have patience until you find it or you may waste a lot of money.

    An amp in the shop never sounds like the same amp when you get it home.

    I bought my BC30 above as a cheap amp with the intention of fixing it, there were a lot of threads about this at the time. Modifying a PCB amp is not easy. You also have to drill holes in its front panel. Modifying an amp destroys its resale value, except speaker swap. One of the easiest things to do to fix an amp's tone is swap the speaker, not a cheap hobby, you have to have an intuition for the right speaker to provide the sound you want.

    OTOH the BJr is one of the quietest "15 watt" combos out there, because the box is too small, and it has an MV.
    I did have a BJr. I found out why I liked when I got it home, it sounded like the middlin' positions of the L5T. But it didn't go as far as the L5T and A/B side by side, it was not much louder. They sound good but I've seen them gigged and they struggle in a 100 seat hall unless they're mic'd into the PA, where other "15 watt class" combos have no such problem.
    That said, the "15 watt" amp is usually too loud for the home, they are intended as small stage amps. A few do turn down nicely, the majority don't. If you want them to turn down for parlour use, they need that MV built in from the get go.
     
  6. muptup

    muptup TDPRI Member

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    Had a few days to get used to the amp. I'm not going to pretend that it's the perfect sensible solution, and yeah the heart was involved as much as the head. The sensible solution I think would've been one of those nice wee Yamaha simulator amps but there's no fun in that.

    The Pro Junior sounds fantastic. I can't overdrive it but the clean tone is great. The volume's usually at 3-4 and my girlfriend verifies that that's an acceptable level. To be honest I haven't even plugged my pedals in to it yet, I'm not bored of that tone yet, probably the longest "clean" practice sessions I've had since I started playing.

    Basically this is what I wanted from my amp, a great resonating tone.

    The amp is already modded (big pine cabinet to fit the 12" speaker) though I don't yet know what if anything's been done to the electrics. I'm not yet bored of it or looking for it to do lots of different things. When that day comes getting drive may be high on the list but not yet :)
     
  7. muptup

    muptup TDPRI Member

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    As for the Blues Jnr. There was something harsh in the sound that I didn't like. It's obviously a personal thing as loads of people love them but it was £100 more expensive for an amp that I just didn't like.
     
  8. tap4154

    tap4154 Doctor of Teleocity Ad Free Member

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    L-Pad and a switch on the negative feedback loop will solve that. Switching off the NFL allows it to break up earlier, and L-Pad allows you to play with the amp on 5-6 with great OD at apartment-friendly volume. Also more saturated/dynamic cleans than playing a stock PJ at 2-3.

    [​IMG]

    Purple wire is the NFL. Just cut it and put the DPDT switch in. You could just cut the wire but it's better to be able to switch it back on if you do play out at higher volumes. It gets real messy at high volume with the NFL off.

    L-Pad: http://www.simplyspeakers.com/speaker-crossover-l-pad-a-542.html

    You can also get a larger 100 watt L-Pad which is really better, and just build an outside-the-amp box for it instead of making the internal configuration I made. Especially if you plan to run the amp volume above 6-7, the 30 watt peak L-Pad I used will get very hot, but a 100 Watt one would be fine.

    I recently put an RC car motor heat sink on the case (snapped right on) and the L-Pad doesn't even get warm when playing amp volume 5-6 with the L-Pad just cracked open.

    [​IMG]
    [​IMG]
     
    Last edited: Dec 12, 2013
  9. Bulldog87

    Bulldog87 Tele-Afflicted

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    edit.... I didn't read far enough!

    Cool purchase... keep us up to date with how you like it in the future!
     
  10. Racing

    Racing Tele-Meister

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    No no no no...
    PPIMV is by NO means Marshalls invention. Like about anything else nuthin much new under the sun.

    Like ultralinear setups..new? Uhm..no. Not really. Dates,like many other insights on the matter,back to the 20s. In the case of UL Australia i believe..

    As stated elsewhere i build a lot of toobers. It is part time what i do. To demonstrate what a PPIMV install does..

    http://www.youtube.com/watch?v=gms2jhlHQr8#t=0


    Hope you´ll survive me being tutorial in Swedish..:D
    Anyways. That there is a minescule little 18w PA by Geloso back in the mid -60s in Italy. A mere ~7kg worth. It sports two 12AX7´s,two EL-84s and an EZ-81 as rectifier. Push/pull of course..a regular longtailed pair phaseinverter set up "my" way...and..a PPIMV pot.
    In this case what that brings is that the distorion,attitude asf you hear in the clip can basically be retained down to bedroom levels. Easy,cheap and effective.
    ´N the other way around...i´ve had it along for a number of gigs lately. Blasting away through the same Echolette 212 box you can see in the clip.
     
  11. muptup

    muptup TDPRI Member

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    Thanks Racing and Tap4154, I'm still a little unclear why I should choose PPIMV vs an L-pad. Both seem relatively straightforward mods, cheap to implement, and achieve similar things. The L-pad does have the advantage that it's very easy to undo the changes.

    Any other thoughts on the benefits of one over the other?
     
  12. tap4154

    tap4154 Doctor of Teleocity Ad Free Member

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    I have no expertise or experience with the PPIMV, but as you said, the L-Pad is cheap, and non-invasive. I love it. One thing is you lose a bit of treble, but I just keep the amp's tone on 12, and adjust it with the guitar tone pot. I love it. I have seen folks make L-Pads with a treble bypass cap as well. Schematics on the net, and probably here as well.
     
    Last edited: Dec 13, 2013
  13. blues bondsman

    blues bondsman Tele-Afflicted

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    Here is my little home brewed practice set up.

    First the head:
    a VHT Special 6 that you can find for around 150 shipped used all over the place
    I did no mods at all, just stuck an RCA 5751 in the preamp spot and an RCA 6V6GT in the power spot.

    The Cab:
    A broken down Asian Marshall combo amp from a local music store (free)
    I closed off the front with some old wooden slats from an old sled, stripped the tolex off and painted the whole thing a yellowish white, the wife decoupaged the whole thing with pictures she cut from Vintage guitar magazine and clear coated it, The grill cover is from a thrown out 1950's organ, I bought someones Throw away eminence / Fender speaker from a pro jr and now have the coolest 1x10 cab in the world :) and it sounds great too !!!!

    The entire rig cost me less than 200 bucks (tubes not included) and sounds very cool !!!
     

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  14. ezas

    ezas TDPRI Member

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    10" speakers never get any love. And no love for the blackstar HT-1R and HT-5R.

    I have the Champ X2 and it's useful for what I do which is hobbyist guitar tech, so I'm always swapping PU's in and out of guitars. I also use the Blackstar HT-1R as a simple plug it in and play it through some tubes amp.

    Now if I could just get that homemade 10" speak cabinet up to the top of the list.

    Awesome setup Blues bondsman. What guitar is that behind it?

    muptup glad you are enjoying your Pro Jr. Another good plug it in and play amp.
     
  15. blues bondsman

    blues bondsman Tele-Afflicted

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    I'm gonna have to make a sound clip up for that set up, it amazes me how nice that single ten sounds.
    The guitar is an Alex Chase (PRS wanna be) Imported from the samick plant a few years back from a guy who's kids were named Alex & Chase, its a real sweet player with well defined pickups (not typical muddy Asian sounding). I had two, a green quilt burst and the orange one in the picture.
     
  16. JAnderson

    JAnderson TDPRI Member

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    "I can barely hear out of my left ear these days." - Edward Van Halen
     
  17. sbpark

    sbpark Friend of Leo's

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    Buy an old Fender Champ.

    But the AC4 looks like a sweet little amp, and they seem to pop up used here in the States pretty frequently in my area for $200-$220 which seems like a great deal. A Silverface champ would cost you more, and may have to have some work done to it. Although you mentioned that you want an all-tube amp, one non-tube amp would be a Yamaha THR-10. It's a really fun little amp, and IDEAL for a small space. I live a small condo, and out of all the amps I have (Bassman LTD, '68 Band Master, 70's Champ and the THR-10) the THR-10 gets the most use.

    [​IMG]
     
  18. Gnobuddy

    Gnobuddy Friend of Leo's

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    For a couple of years a Super Champ XD was my only "tube" amp (hybrid, actually). I found myself strongly preferring the clean channel (no amp modelling), but only at volumes too high for the home, where I do 99% of my playing. Then I discovered the L-pad via a few posts by one "Jeober" on TDPRI in the SCXD owners thread.

    For me, the L-pad was an almost immediate solution. Late at night I would set the amp on one of those TV-tray (little folding tables) and sit down on the couch so the amp was at ear height and no more than three feet from my head. This put my head in the near-field region of the speaker, which brings back some of the bass and treble you otherwise lose at very low volume - it's the same idea used by recording and mix engineers with their near-field monitor speakers. With the amp this close to my ears I could then use the L-pad to turn down the speaker volume to almost nothing. My wife could sleep in the next room, and my very elderly neighbour twenty feet away across the driveway would never even know I had an amp on.

    There were two main problems with the L-pad for me. The first one was that it ended up set almost entirely at the zero end of the dial, which made it "twitchy" to adjust the volume, and also increases the likelihood of burning out the L-pad (all the heat is dissipated in a tiny fraction of the resistance wire inside it). I fixed that by building a fixed sixteen-times attenuator with a few cheap 10 watt power resistors to cut the power from the SCXD output transformer to roughly 1 watt (from roughly 16 watts). The 1 watt output of the fixed attenuator then went to the L-pad, which dialed it down further to whatever level was necessary for quiet night-time playing.

    Amazingly if you're used to the idea that you need a 30 watt amp to play in a closet ( :p ), it turns out you actually only need a few hundredths of a watt to play quietly at night with the amp close to your ears.

    The second problem wasn't really the fault of the L-pad, but of my ears - at low volumes our ears become less sensitive to bass and treble (Google "Fletcher-Munson loudness contours" for more), so the amp didn't sound as good. The easiest fix is the one I already mentioned - bring the amp very close to your ears, so you hear the near-field sound, which is much bassier. Fine-tune the tone controls for the rest.

    With this setup I had no trouble getting very good clean "tubey" tones at very low volumes. But I never really solved the problem of getting good driven tones - I don't enjoy the digitally modelled sounds in the SCXD or just about any other DSP modeller I've tried. Also I prefer to have reverb after distortion, and that means either you play guitar in a huge reverberant room, or you do your distortion at line-level and put electronic reverb after it, before the signal ever gets amplified and hits the speaker. I've had decent results with some pedals, but nothing so good that it thrills me to the marrow, so to speak.

    There are two oddball alternatives I've tried, and I'll mention both. One is an inexpensive little cigarette-pack-sized DSP modeller/headphone amp called the Nux PG-2. It's around $40 on Amazon, and it is the only DSP guitar amp modeller I've ever heard that has no detectable "grit" or low-level harshness in the sound. I'm not convinced I like the actual sounds, but at least they aren't harsh and don't immediately fatigue my ears like the Fender and Line 6 and Zoom and Digitech other similar products.

    There are several amp models in the Nux PG-2, and if you like one or more, this may be a perfect solution - just remember to keep headphone volumes very low, because 'phones are a perfect way to permanently destroy your hearing through excessive volume.

    I couldn't find a single good demo of the PG-2 on Youtube, but I did find some decent demos of its predecessor, the Nux PG-1. Here's one of those clips. It's not in English, but you don't need to understand the player's words to listen to the guitar tone! Skip ahead to about 2:00 to hear the guitar and skip the patter:



    I've saved the best oddball alternative for last. I stumbled across the Joyo amp emulator pedals a while ago, and was blown away by the first one I heard, the American Sound. These aren't digital, they are all analogue, and they really sound astonishingly like a good tube amp once you get the levels and tone controls set properly. There isn't enough output to drive headphones, but you can run the output into any small clean amp (even computer speakers) for late-night playing, or buy a cheap headphone amp or something similar.

    Here is one fascinating and thought-provoking clip of the Joyo American Sound in action:



    -Gnobuddy
     
  19. Gnobuddy

    Gnobuddy Friend of Leo's

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    They do look sweet, and seemed about the right amount of power for home use, so I bought one when they first came out. Unfortunately it had a very boxy sound that I could not tolerate and could not dial out, so back to the store it went.

    As usual, your ears and brain may or may not hear things the way mine did.

    -Gnobuddy
     
  20. Commodore 64

    Commodore 64 Friend of Leo's

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    The more I play my single 12 amps (Blues Deluxe and a Traynor YCV40), the more I appreciate the little 10-inch speaker in my Pro Jr. This isn't to say I'm not pleased with the 12-inch amps, especially for playing out. I like them both.

    I can honestly say, though, that I still like my Pro Jr just as much as I did before (when it was my main amp).
     
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