Why horrible????????
You have basically 2 x TDA2030 or LM1875 inside; use just one channel to drive your excellent Jensen speaker with some 20W RMS; bridging them will be too much power.
There is no harm in leaving one channel unloaded, doubly so if you ground its input.
Or you can connect the unused channel output to an extension speaker jack, and plug any available speaker there to annoy the neighbours when needed
You will still need to build some kind of basic Guitar preamp to drive it, OR drive it from any pedalboard ... even a simple Distortion pedal which can be used by itself like a crude preamp.
You have basically 2 x TDA2030 or LM1875 inside; use just one channel to drive your excellent Jensen speaker with some 20W RMS; bridging them will be too much power.
There is no harm in leaving one channel unloaded, doubly so if you ground its input.
Or you can connect the unused channel output to an extension speaker jack, and plug any available speaker there to annoy the neighbours when needed
You will still need to build some kind of basic Guitar preamp to drive it, OR drive it from any pedalboard ... even a simple Distortion pedal which can be used by itself like a crude preamp.
I've read lots of negative articles on SS guitar amps and wondered if this would be just another poor sounding attempt.
Or you can connect the unused channel output to an extension speaker jack, and plug any available speaker there to annoy the neighbours when needed
That is a great idea!
I'm going to put a NE5532 preamp with basic tone controls in front so that should take care of that.
Do I need to make any considerations regarding impedance?
Thanks.
Last edited by a moderator:
That´s what people who CAN NOT PLAY write, and blame the amp for their own faults.[\Quote]
Of course, they DO NOT have a Tube amp, but imagine good sound from , say, Van Halen, Hendrix or Megadeath to name a few comes from their using tube amps.
But "tone is in the hands" first and foremost, of course amp helps.
Just watch this video, from a collector who has all the amps in the World, playing with the cheapest transistor Marshall, using the lightest cheapest 10" Celestion fitted to it:
YouTube
Build an SS **guitar** preamp ... such as the very simple one used in the Marshall lead 12 above.
Just one dual Op Amp (TL072/RC4558/etc.)
For an even more incredible but true example, Johan Segeborn using the absolute cheapest generic SS amplifier, the one typically bundled in the "guitar + amp + cable" $199 packs.
Although this time he plugs it into a "good" speaker.
YouTube
please listen and comment what you *now* think of properly used SS amplifiers
Oh, boy. Here we go, walking across one of the guitar world's oldest and biggest minefields!
This is a genuinely difficult topic to discuss, in large part because "electric guitar" covers such an extraordinary range of sounds, and so do personal tastes.
I will say that - in my opinion - I had bad electric guitar tone for 25 years of using a wide variety of home-made and commercially manufactured electric guitar amps, and a variety of different guitars. I sounded decent enough on acoustic guitar, but never on e-guitar. I was really frustrated, and didn't know whether the problem was me, or my guitars. (It never crossed my mind that *all* the amp's I'd tried could have been that bad.)
Then I tried my first valve (hybrid, actually) guitar amp. A minute after plugging in, I was hearing the best sounds I'd ever heard coming out of an electric guitar in my hands, and my jaw was heading for the floor.
I should add that I grew up (literally) with solid state electronics; I built my first circuits at around age eight, and was designing some of my own circuits by the time I was sixteen. All I knew of valves was that they were ancient, obsolete, and had been replaced by much better devices - transistors - before I was even born.
So I didn't walk into e-guitar with a prejudice against transistors. Actually, I walked into e-guitar with a prejudice against valves, which is one of the reasons why it took me 25 years to try my first valve amp!
I like clean guitar tones, or very nearly clean. IMO, this is where valve amps shine best. If your e-guitar sound of choice is heavily distorted, there is much less difference between valve and SS amps; a buzz-saw pretty much sounds like a buzz-saw.
Since this entire topic is about personal opinion, I'll go a little further. In my opinion, the videos of Segeborn playing cheap SS amps and producing apparently good sounds from them are little less than a Potemkin village swindle ( Potemkin village - Wikipedia ).
Segeborn is a fantastic guitar player, no doubt of that at all; however, listen to how little treble is actually in the recordings. Heavy EQ has been used somewhere in the recording chain to diminish the nasty harsh treble these amps actually produce. I can virtually guarantee that if you were in the room with the amp, it would sound much harsher. In the same vein, close miking and bass EQ has been used to remove the boxy sound of the nasty little enclosures, and to create bass in the recording that sounds nothing like the bass from the actual amp when you're standing in the room with it.
Note also that Segeborn never spends any time playing any actual clean tones in either of those two videos. If he had, one might have noticed one of the worst qualities of this type of SS guitar amp - thin, cold, sterile-sounding clean tones. (Or one might have noticed the extremely dull sound caused by the heavy treble cut Segeborn used in the recording chain.)
So does that mean you (AVtech23) will be wasting your time if you build an SS guitar amp of the sort you're contemplating? I have no way of knowing. If your ear/brain/musical taste works like mine, then yes, you will hate the sounds the amp makes. But it's also true that music shops all over the world sell solid-state guitar amps designed exactly like this (op-amp preamp, chip-amp power stage) by the thousands, and presumably, thousands of people play them with enjoyment. You may feel the same way they do, for all I know.
After a lot of years of experimenting and thinking about this, what I've come to believe is that the electric guitar (especially the solid-body variety) is inherently a rather nasty-sounding instrument, thin, cold, and harsh. Plug into an SS amp based on a precise, accurate op-amp and a precise, accurate power amp, and that same thin, cold, harsh character will be relayed accurately to the loudspeaker.
That being the case, IMO what is needed to make e-guitar sound good is the aural equivalent of rose-coloured spectacles: an amp that flatters the sound, sandpapers off the rough edges, adds subtle harmonics to fill out the thin sound, squashes down the harsh abrupt transients that every note starts with, and adds progressive distortion that rises and falls in sympathy with playing dynamics. Add in some reverberation, maybe a tiny bit of echo/delay, and now that harsh electric guitar might actually sound fairly good.
How do you make an amp like this? Avoid precise and accurate amplification. Use devices that have nonlinear gain (squashing transients and adding subtle harmonics). Valves are one possibility. JFETs or MOSFETs are another, especially if you play some tricks on them ( a very clever Russian engineer who goes by the initials "KMG" published some stellar circuits using MOSFETs, but his website seems to be down now. ) Don't use lots of open-loop gain and lots of negative feedback; want an amp that's inaccurate and nonlinear, not precise and accurate.
I will add that I have great respect for JM Fahey's opinions on pretty much every technical aspect of guitar amps and related topics. However, it seems we disagree very strongly when it comes to the sound of the typical budget SS guitar amp. Which is fine, I bet my top three favourite foods aren't the same as Fahey's, either.
-Gnobuddy
I didn't listen to the whole video, true. Let's just say that I'm a skeptic until (a)I'm in the same room as Segeborn and his amp, listening with my own two ears, and (b) I hear Segeborn play some 100% clean stuff through either of those amps.
No doubt a very good player can extract the best from even a "pants" amp, and also no doubt heavy EQ in the recording process can make the recorded version of that amp sound better than it actually is.
One characteristic of every good traditional musical instrument is that the harmonic spectrum gets dirtier as the instrument is played with more intensity. Op-amps and chip power amps don't do this at all - they are perfectly clean until they run into abrupt harsh clipping, a characteristic of high amounts of negative feedback.
In the end, this is one of those online arguments that never end, and I feel it would be counterproductive to go back and forth. AVtech23 will just have to find out for himself, with his ears, his guitar, and his hands.
To those who like the sound of small SS amps in little boxes, all I can say is, lucky you - you can get sound you like with far less trouble than I can!
It's not that I haven't tried - in fact, I have been playing through an entirely SS chain (various FX pedals, speaker emulation filter, into P.A.) for some months now, because I got tired of hauling so much gear. Even with EQ, reverb, and delay, and using a semi-hollow guitar (ES-335 copy) which sounds better than a solid wooden plank, it still doesn't sound as good as a tube amp. To my ears, obviously.
-Gnobuddy
i don't think "heavy" EQ was applied in the record process, near the end of the Epiphone amp vid in the "panel" on the right, there's an outline of the equipment used and record processes, all for the purpose of being forthright about what being presented.
old soundman adage "he who eq's the least, eq's the best"(if the source is good no need to massage it)
old soundman adage "he who eq's the least, eq's the best"(if the source is good no need to massage it)
Last edited:
Thanks for the tip... I just had a read through a few threads that talked about NE5532 being inappropriate for a guitar preamp due impedance, and being pointless as a buffer due to adding another stage of noise. Those also pointed toward TL071/072 etc so I'll keep looking along those lines.
For the Marshall circuit, what would be your IC of choice?
please listen and comment what you *now* think of properly used SS amplifiers
Ok, that was pretty good! I might need to pick up a $10k Les Paul reissue and probably a lifetime worth of lessons before I can sound even half as good!
Oh, boy. Here we go, walking across one of the guitar world's oldest and biggest minefields!
Sorry to open a can of worms!!
I'm quite happy to explore making and modding different amps just for the experience. If it doesn't sound great at the end, I can either keep tinkering or pass it on to someone that does like the sound. Either way, I'll take the education as the enjoyment.
I do have a 'craptastic' practice amp in the back of the cupboard somewhere. I didn't particularly like the sound it made which is why I went valves and built a Princeton circuit, but I wanted to explore SS a bit more before settling on a preferred taste. I might even dig that one back out and pull it to pieces to see what's inside.
Thanks for the tips. I'll have to see what I can find r.e KMG.
Hate to quote myself but I found this page which has some good info r.e. different op amp choices and how they sound.
Op-Amp Questions, Marshall 3005 | MarshallForum.com
I might give the RC4558IP a go at $0.60 a pop: https://au.element14.com/texas-instruments/rc4558ip/op-amp-3mhz-1-7v-us-dip-8/dp/2114058
Would that be suitable?
The original one uses cheesy 1458 ... I bet Jim Marshall had bought a zillion of them (not kidding, I bet he "swept the factory floor" when they were discontinued, he might have paid 10/15 cents each) but TL072 is perfect there, the 4558 you found too.
As a side note, I very much doubt Johan Segeborn used "heavy EQ" on the cheaper amps.
He´s not an SS evangelist by any means, quite the contrary, he is "the" quintessential Tubehead, just watch his other 500 or 600 videos, he has nothing to gain and a lot to loose by pushing cheap SS amps against his beloved and huge Marshall collection.
If anything, it pays for him to be honest and trusty.
His recording setup is consistent for *all* of his tests: one microphone stuck against the speaker grill, another far away , usually behind the camera so invisible, to supply room ambiance and natural reverb.
To be more precise
n the second video he does use better EQ: he goes through a good speaker!!!!At least 50% (or more) of the bad press SS amps get is due to their invariably being coupled to cheesy dismal speakers,I suggest you use a good one.
No need to get into financial trouble: either buy a Jensen MOD speaker, good and inexpensive, or get some "factory speaker pull": lots of people improve their combos and cabinets by fitting better expensive Celestion/Eminence/Jensen/WGS/Weber/Scumback/Fane speakers and have no use for the old ones, often they sell them for $20 or so on Craigslist or some garage sale.
Now most American made 70´s to 2000 something amps used one type or another of OEM made Eminence, just with an own Brand label.
So Fender blue label "Special design", Randall "Jaguar" or Crate/Ampeg/Peavey "black painted frame" speakers are actually same as Eminence Legend series ... not bad at all.
Since "sound" is better example than "written words", here´s a customer selling his Fahey amplifier.
This is the cheapest one I made, 30 years ago (1988) .
We were going through hyperinflation then, (think Venezuela today) , NO imported stuff was available, including ICs , so I had to "stretch" my last "stick" of TL072.
So instead of my then current preamp (5 x TL072) I started building a stopgap interim model, based on a modded Marshall Lead 12 preamp coupled to my 100W SS amplifier (back then based on 2N3055 transistors).
Listen to it, recorded on a cellphone, raw, zero editing or post processing, played by an average user on a *cheap* guitar.
No EQ, Pedals, anything, just guitar>cable>amplifier.
As I suggested you do, it´s played through an average Fender cabinet, which means a Fender branded mid price Eminence.
People loved it, eventually sold about 3000 of them.
YouTube
Your chipamp will sound similar or better, quite usable in any case, if played through a decent speaker.
Last edited:
i just got done watching that utoob vid with the Fahey 3600 at the 2:30 mark the guy playing it backs the drive and distortion off and gets a clean tone that grows "hair" with playing dynamics is that the quality that Gnobuddy was talking about earlier?
i'm starting to think Mr Fahey is the Pete Traynor of Agrentina!
i'm starting to think Mr Fahey is the Pete Traynor of Agrentina!
I think part of the spectacularly awful sound of some of those little amps is just the acoustics of the tiny open-back cab. If you stick your head into a small plastic bucket and talk or sing, you get a clear demonstration of just how bad a hatchet-job those acoustic cavity modes do to the timbre of a sound.
And IMO that's absolutely worth doing. In my mind, there are a thousand reasons to go SS, and only one reason not to: I can't make an SS circuit sound as good. To my ears and brain, obviously.
At the end of 2017, I decided to build a guitar amp to give to a senior-citizen friend of mine as a Christmas gift. It had to be solid-state to fit my budget and his physical handicap (weight limit), and I spent quite a bit of time trying to make a solid-state guitar amp that didn't sound like @%$%%^!#. In the end I managed to get decent clean tones out of it, without the harshness of the typical SS op-amp/chip-amp combination, but also without the lushness and richness of a good valve amp.
I did have a diyAudio thread on that project: Tube Emulation & EQ . There was some discussion about KMGs MOSFET triode-emulation circuits in the thread, and one of the main participants went ahead and used KMGs ideas to make a solid-state version of a typical Fender Blackface preamp. I think he showed his circuit, which should still be there, as it didn't depend on KMG's now-defunct website.
This is (was?) his website: http://milas.spb.ru/~kmg/index_en.html
Unfortunately, I have been unable to connect to it lately. I don't know if the site is down temporarily, or is gone for good.
There is a longish thread on the SS Guitar forum ( Fet version of the JCM800 ), but most of the interesting external links were to KMGs website, which is now down, so those links are gone, too.
I remember thinking years ago that I should mirror his website onto my local hard drive (using the magic of the Linux program wget), but I'm not sure if I actually did so, or not. I'll look through some of my old backups to see if I can find anything.
-Gnobuddy
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.