I have some early-style Acoustasonic Jr. experience, if you have any questions about them from a sound/playing/functionality standpoint. But I don't know how model and production changes relate to particular dates. I think mine's a '97 or thereabouts, and has spring reverb instead of the later DSP version...

Interesting thread, even to a guy like me who's about 27,000 light years behind you guys in terms of electronics comprehension. Sag is a big deal to me; I'm very dependent on an amp having a certain response "feel" to do what I do. So I can relate on that level.

I will say that, as an electronics-using caveman, my own sag needs are currently pretty well met by running a compression pedal after a Rat II, which is set with the gain very low and the output very high so it isn't compressing the signal too much on its own, just adding a little grit and harmonic content. Maybe one of these days I'll have learned enough to approach this by actually building something the way you guys have, rather than just plugging things in in a certain order! Carry on...

Also...I have GOT to try one of those Blues Cubes one of these days.

Hey, BPJ, congrats on the new amp...I'll be interested to hear how you like its tone, and whether you can find an innate amp tone in it that works for you or whether you end up using it alll ZOOMed (tm) up. Having the top-mount chassis at the front of the cabinet is an interesting departure from tweed-inspired rear-top chassis amps.

Does it have a line out jack? I ask because I had just about decided that I did not like my Dean Markley K-20 amp (sorry Joecool) when I decided to run its line out into a separate power amp and speaker and found that it became an entirely different amp. Apparenty my issue with it has been the cabinet design and/or its stock speaker. Taking those out of the equation warmed it up and sounded fuller, and seemed to give it a lot more punch.

On the other hand, my other little SS amp (Peavey Audition 20) sounds great to me through its stock speaker and sounds worse in every other line-out scenario I've tried.

Yeah...sometimes I ramble a little. Good to see you back again!

Mine did a pretty good job of driving a 2 x 10 cab I sold recently, loaded with a pair of 50-watt SLM speakers. Wish I still had a 4 x 12 sitting around to try it with!

The X models might be different, but to my ear the pre-X K-20 has a pretty lazy transient response, and I'm not sure if that's a power supply limitation, or a specific attempt to emulate a saggy tube rectifier, or what. My early 80s Peavey Audition 20 seems to have a lot more clean headroom and feels a lot "faster" in terms of transient response.

On the other hand, I recently discovered that if I put a compressor pedal in front of the K-20 and set the amp's input gain about halfway, the bass about 1/4 of the way up, and dime everything else, the K-20 goes nuts with sparkly upper mids and loose, wild-ass lows...kind of like Joe Walsh's James Gang-era tones. It makes me think of cranked tweed Fender, sort of. I'm happy to discover something that amp can do that my other amps cannot.

Nice work, and nicely documented! I like your Squier Tele too...that's a neat orangey vintage finish.

This is an inspiring thread, because I've got a pre-X K-20 that's working but pretty ratty, with paint spills on the tolex and a cracked MDF baffle board. Not sure if I just want to keep it around as an extra flavor of small amp, or if I want to get creative with it.

I've considered removing the chassis and making it into a pedalboard-mounted amp, so I could just carry my pedalboard and a small cabinet for low-volume stuff.

I've also thought about swapping in a 4-ohm 8" midbass/PA-type driver and enclosing the back (below the chassis) with some cleats and panels screwed/glued in place, and using it as a bass practice amp. Not sure I want to get that non-reversible with it, but at very low volumes, it sounds excellent with a P-bass (drive channel set with gain very low--1-1/2 or 2--and the output vol halfway or more). Even with the stock speaker and open-back cab, I bet it'd be a great bass recording amp, miked up for some low-volume grunt and twang and combined with a clean, maybe compressed, DI for lows... 

This brings back some memories; my first "real" amp was a KMD GS130D, which was a solid-state 130-watt 2 x 12 combo. It's been out of my fleet for years, but as I recall, it had a big, fat-bottomed distorted snarl and it could get REALLY reverbed out. I probably spent about 19 seconds on the clean channel in all the years I owned it.

Looking back now, I wish I'd kept it and experimented with its lower-gain sounds, now that I've gotten my tube-snobbishness out of the way.

First off, apologies for already asking the question about horn length/phase relationships before...I just stumbled across a thread where I asked you the same damn question, and you answered it in just as detailed a manner, and my response sounded like I read and understood what you said.

Then I apparently filed it in a mental black hole. So, thank you for taking the time twice!

Both the post above and the link to your comments elsewhere were interesting and informative; thanks for those too. I'll try not to ask all the same things over again in six months this time. Maybe I'll have undertaken a J-bin project by then...

Thanks as always for taking the time to think about this and offer suggestions.

Why do you recommend rear-mounting the speaker onto the baffle board, whether through a removable top or onto the back of a removable baffle? What is the disadvantage of just mounting the speaker's flange onto the front of the baffle board? Is it just to make grille coverage of the cone easier and more flush? Or is there a mechanical/structural reason I'm unaware of?

Second question: is the length of the horn calculated to add in some time-of-arrival difference, so that the sound coming off the front of the cone and the sound coming off the rear of the cone and through the added horn length emerge in phase with one another?

Third question: Is there any reason why a rear horn-loaded J-bin wouldn't work on its side, in horizontal orientation? Is the stood-up vertical arrangement required for some acoustic reason, like, maybe what's coming out of the horn is strong in the lower frequencies but limited up top, and all the 500 Hz and above (or whatever range) is coming only off the front of the cone...and having it standing up gives better distribution to all possible listening positions?

More and more I'm liking the idea of covering a cabinet with a coating like truck bedliner compound, or that industrial Durabak paint that has the rubber crumbs in it for traction...instead of tolex or animal-hair-and-chaff-collecting live PA carpet stuff.

More great info; thank you. I will add this to the Fane packet. I'm getting psyched up to try building one of these.

Your comment about running the tweeters padded down for just a taste, rather than full out, made me think that I'd benefit from devising a way to turn my acoustic amp's tweeter up and down relative to the main drivers. I'd have a better idea then of what a tweeter can add before it gets too "present," with different sound sources.

I've seen speakers for sale with so-called "whizzer cones" protruding from where the voice coil dust cap would normally be. Is this to allow a conventional driver to sort of fudge its way into approximating an upper-range driver? Does this practice sound especially good or bad for any specific uses?

It's cool to encounter some love for small Peavey SS amps, and the Spongebob Squarepants-grilled Rage sounds like a really cool project. My first amp as a kid was a Audition 20, and I still have it and use it all the time. Interestingly, I find I usually have the pre gain around 6 and the post gain at 4 or above...same settings shown in your photo!

On mine, I kept the silver stiffening strips on the sides of the grille, but removed the spiky stoner Peavey logo and added a red and white International-Harvester "IH" logo. I like amps to look like tractors.

I look forward to reading about the OP's progress with the Blazer.

Roly, I "favorited" your link to the J-bin plans that you posted awhile back. That does look like a cool project, and one that would take my carpentry skills to the limit but might still be possible.

I have a recently acquired a Peavey M-3000 monaural power amp (210W into 4 ohms; 300W into 2 ohms) with DDT compression, currently sitting around idle looking for something to do. If I could decide on a preamp I liked and built a J-bin like you describe that I could still lift and transport...hmmmm.

In your keyboard playing, have you found tweeters that handle distorted textures particularly well? Not sure how best to phrase that, but I haven't spent much time thinking about tweeters or listening to them comparatively. I know the piezo tweeter in my acoustic amp is generally unpleasant with electric guitar--even electric guitar fed through a speaker simulator--unless you EQ the bejesus out of the signal.

But I too have noticed that it adds a nice crisp edge to a bass guitar at the low volumes I've been using.

Thank you for the information and suggestions. I'm going to be thinking about drivers, tweeters and keeping my fingers intact for bit, and will likely be back to ask you more questions.

Just checking in after being away for awhile, and what a great thread to check in on! Lots of info here, presented in a no-nonsense but articulate manner.

As a longtime guitarist and beginner bassist, this subject interests me too. I'd love to have one rig that sounded good enough to me to use with both instruments, so I could declutter my basement and feel less guilty about the various dusty items I don't use as much as I used to. I've been experimenting with a few different combinations in the past year, with one main goal being to look for guitar/bass dual capability.

It's beginning to look to me like there are some seriously different opinions about what constitutes good bass tone. To me, my P-bass copy, played fingerstyle with an ear more towards midrangier R & B-ish sounds, sounds pretty decent through any simple amp with a three-band EQ and just enough gain to achieve the threshhold of distortion, and the speaker configuration just limits how loud I can play. One of the tones I've liked best so far is a little Dean Markley K-20 guitar practice amp, on the drive channel but with the gain low. It's bright and gritty, but if you back off the volume and tone pots on the bass itself, it can sound natural and warm at low volumes...like, practice-along-with-a-smal-boombox-volumes. Of course, it's very easy to achieve "way too loud for the little 8" speaker to handle" levels with a bass, too, so you have to be realistic.

I've also liked the tone of the bass through my Fender Acoustasonic Jr. amp, which is basically a full-range PA-type amp feeding two 8" speakers and a single piezo tweeter. It's cleaner and more "modern" sounding, but it sounds good to me too.

I do not find that I can plug my guitar into any old bass amp and like the tone. But I have found that my Line 6 1x10 bass amp can achieve good sounds with either instrument (and my lap steel)...but it requires pretty radically different settings to do so. The factory model presets sound pretty decent with bass as-is, with some improvement possible, whereas it takes some pretty serious bass and low-mid cutting to get the guitar tones. But they're there.

Jim, I heard a bassist friend of mine get some pretty good (quiet) tones on a recording by running his J-bass into a silverface Fender Deluxe Reverb. I bet that Princeton does sound nice.

Does the 10-watt Prime amp have a line out jack, or a headphone jack?

If you really like the tone of the Prime amp, but it's not loud enough, as your first post states, it would make the most sense to me to "slave" the Crate G60XL off of it. In that scenario, ideally you'd take a line level signal from the Prime's line out (if it has one) into the Crate's line in (or the return jack of its effects loop). The Prime becomes the preamp, bypassing the Crate's preamp, and feeds the Crate's 60-watt output stage and 12" speaker. It's not even that silly, if you just consider the Prime to be a slightly bulky effects pedal that happens to have a speaker in it. I do a similar thing using a Peavey Audition 20's line out feeding various other amps sometimes, and I am not silly.

Never. At all.

If the Prime does not have a line out jack, sometimes a headphone jack can work for that purpose. Or, possibly better yet, you can just add a line out to the amp. I haven't done that yet myself, but there are members here who can tell you the couple of different resistor values you need and how to connect them to the speaker wires. Here's one article on the subject:

http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/Mods/ezlo.html

Joecool85 has mentioned on this forum that he added a line out kind of like this to a no-line-out Dean Markley practice amp; you might do a search for "Dean Markley K-20X" and see what you find.

If the Vox unit you're thinking of is the Tonelab, which is sort of a floor processor with a preamp tube in it, I've been told by at least two people that those things have some good sounds in them, and I've heard recorded examples by one of the guys who told me that. I'm sure one of those could achieve a range of bluesy overdrive tones.

But my inclination would be to say that you have an amp that is not too common, which probably has a unique tonal personality of its own, whereas you could plug a Tonelab into anything and sound like you were using a Tonelab.

I'd be in favor of trying everything you can try with that Yamaha amp and see if it can do something unique for you before putting it downstream of some unit that imposes a different personality. Not too many people can say they are cranking a G100-115 these days!

Have you ever tried a Boss SD-1 Super Overdrive? The yellow one (not the more distorted, midrangy and orange DS-1 Distortion)? Something like that, with the gain set pretty low and the level set pretty high, might give you relatively natural-sounding light clipping.

Also, some say combining compressors and distortion pedals is counterproductive, since distortion effects tend to compress the signal anyway, but if you compress the signal before you hit the distortion, it can affect the level and character of the distortion you get...sort of like rolling back your volume knob to clean your tone up. It's more about imparting some control onto the signal into the distortion, to limit how much it will distort, rather than controlling it to get it to sit right in a music mix or whatever.

I've gotten some cool medium-gain tones from a Rat II pedal by running a compressor in front of it...the Rat II is nobody's idea of a subtle effect, but by playing with the attack, compression and output level controls on an old DOD compressor pedal I was able to mellow that Rat right out, leaving a lot of the harsh fizzy/fuzzy bite and just getting a nice smooth grind.



You might also find that skipping the distortion altogether and cranking your Yamaha up a bit with a compressor in front of it can give you  sustain and the kind of enevelope you'd get playing through a cranked tube amp, and that you don't miss the distorted toothiness anyway. It's something to try. If you're really after a singing, sustainy and blooming sound to do bluesy single-note phrases, like B.B. King might, consider his tone...punchy and sustainy, but pretty clean. You don't usually hear him, or SRV, to name two obvious blues guys, playing crunchy power chords...so maybe if you're really after that playing approach, you don't need a distortion pedal so much as volume and sustain.