Old Acoustic amps vs modern power amps

[garmenteros]

I owned an acoustic 370 and sold it to a friend, I ran it through my mesa powerhouse 1000 and it got unbelievably loud... As loud as my mesa400+... I loved the vintage sound of this head... I have a chance to get an acoustic b150 for about 150$ all original in working order but im still debating if I should get it or not...

 

[Johnny Crab]

Dunno about some of the comments.
During my metal & spandex days, PART of my rig was an Acoustic 370 mated to a 301 cabinet(my side) and a Cerwin Vega B36(?, the half folded small box) for low end and an SVT with one 8x10 per side. Even with the SVT OFF(as it was a few gigs when my SVT cratered once), the 370 never went past 10 or 11 o'clock.

 

[KJung]

I understand what your getting at, a stand-alone head takes a lot of the variables out of the equation. Being someone who uses, and appreciates both types of set-ups my opinion is this:

Having a preamp/channel strip with input and output level control is important. Having the ability to dial-in how hard you want to hit the front end of your preamp, how hard you want to hit the front of your power amp, and lastly how hard you want to hit your speaker cab(s) gives a whole lot of flexibility. If you add the ability to choose between Tube and SS on the front end you've got even more variations in character. The more headroom the better in this situation, I run a PLX3102, it's as loud as any bass head on the market IMO.

+1 This is actually how the TC RH450 works.... pre gain, then post EQ volume, then master. Nice!.

Again, per a few of the comments above, people seem to keep confusing volume and tone. It is VERY easy to get a moderately powered amp loud by attenuating/hi passing the low end and adding a lot of 'clipping/distortion' to the midrange. Nothing wrong with that, and that gives an amp a lot of bite, a lot of grind, and a lot of midrange complexity that results in it sounding loud as heck for the rated wattage. The older GK amps and the Acoustics are great examples of this, and if you like the punchy grind, they are still great.

My point is, there is nothing 'magic' about it, and the more full, deep low end, cleaner mids, and more extended top end of many current amps sounds much better to me... even if that means you need more wattage to reach similar volumes.

The downside to the rack gear (ESPECIALLY preamps not designed for bass) and power amps, besides input gain matching on some combinations, is that they take this widening of the frequency range to extremes. While most power amps have some sort of hi pass filtering capability, some don't, and the channel strip pre's are also voiced very widely, with very little 'distortion' in the midrange. This can result in a HUGELY wide tone with polite mids, which results in you needing a) stupid power to project through a mix, and b) often times runs a cab into xmax/min issues, resulting in the cab not being able to reach its published SPLMax due to a huge amount of sub low end being pumped into it. That's why some of these 2000 watt rigs don't sound any louder than many 500 watt bass amps.

Again, nothing wrong with these power amp/channel strip rigs if you know what you are doing and can hi pass them correctly. Also, nothing wrong with the old Acoustics and GK's as long as you don't think there is some magic going on and understand that distorted mids and attenuated low end means LOUD per watt (at a cost of true low end and THD), and nothing wrong with modern, all in one amps that are clean, wide within reason, hi and lo passed appropriately for bass, and require power higher than the old amps but lower than channel strip type rigs to reach similar volume.

Again, nothing magic about it... it is what it is, and VOLUME is just one indication of amp or rig performance

 

[johnk_10]

The downside to the rack gear (ESPECIALLY preamps not designed for bass) and power amps, besides input gain matching on some combinations, is that they take this widening of the frequency range to extremes. While most power amps have some sort of hi pass filtering capability, some don't, and the channel strip pre's are also voiced very widely, with very little 'distortion' in the midrange. This can result in a HUGELY wide tone with polite mids, which results in you needing a) stupid power to project through a mix, and b) often times runs a cab into xmax/min issues, resulting in the cab not being able to reach its published SPLMax due to a huge amount of sub low end being pumped into it. That's why some of these 2000 watt rigs don't sound any louder than many 500 watt bass amps.

i have run many RTA tests on my bass specific preamps, and on my channel strips, and both of them have a very wide frequency response ( basically flat down to 10Hz), and believe me, my 2000 watt xti amp sounds ALOT louder than ANY 500 modern watt bass head using either a bass preamp or a channel strip (with or without any distrotion), and there is not a huge amount of low end 'pumped into' either type.

 

[KJung]

Dunno about some of the comments.
During my metal & spandex days, PART of my rig was an Acoustic 370 mated to a 301 cabinet(my side) and a Cerwin Vega B36(?, the half folded small box) for low end and an SVT with one 8x10 per side. Even with the SVT OFF(as it was a few gigs when my SVT cratered once), the 370 never went past 10 or 11 o'clock.

This is another issue that seems to add confusion when evaluating the output of amps. The physical setting of a master volume control is totally useless in determining how loud an amp will go, or how loud one amp is from another.

Many amps, especially 'back in the day', used a master volume taper that resulted in an amp reaching its full rated power (assuming appropriate input signal) well before the noon setting.

Amps and master volume taper designs vary greatly. For example, my Glock head and TecAmp heads don't even START to pump until the master volume gets past 1 o'clock (they use audio tapers or whatever those are called). On the other hand, my Thunderfunk and Markbass amps seem to reach full volume (i.e., with appropriate input gain, they start to compress and stop getting louder) at around the 1 o'clock setting.

Other amps, like some of the GK's, seem to reach maximum output below noon on the master.

The key is, the knob position is much more indicative of the preamp design than it is absolute volume capability of the amp.

 

[KJung]

i have run many RTA tests on my bass specific preamps, and on my channel strips, and both of them have a very wide frequency response ( basically flat down to 10Hz), and believe me, my 2000 watt xti amp sounds ALOT louder than ANY 500 modern watt bass head using either a bass preamp or a channel strip (with or without any distrotion), and there is not a huge amount of low end 'pumped into' either type.

That 'flat down to 10hz' is what I'm talking about.... simply awful in many cases in live performance for bass guitar unless you can control it with hi pass filtering (which typically happens at the power amp from what I understand). The old SWR amps had this issue (hi pass set at about 20hz).... speaker pistoning like crazy... sounded amazing in the basement, but the little attenuated GK amps with half the power would bury them on the gig, and actually produce a more useable low end for bass guitar in a mix.

Again, if it works for you, that's obviously cool.

 

[johnk_10]

yeah, but what i'm saying is is that bass specific preamps AND channel strips both go down to 10Hz, so using one type or the other make no difference.

however, this gives most channel strips (like my ISA430MKII and VT737SP) an even bigger advantage, since they have adjustable (variable frequency) low cut filters. plus their eq is parametric so you can dial in or out the exact frequencies that you want to shape your sound to each venue or song.
so your preference of a bass specific preamp or amp, still makes absolutely no sense to me.

 

[KJung]

yeah, but what i'm saying is is that bass specific preamps AND channel strips both go down to 10Hz, so using one type or the other make no difference.

however, this gives most channel strips (like my ISA430MKII and VT737SP) an even bigger advantage, since they have adjustable (variable frequency) low cut filters. plus their eq is parametric so you can dial in or out the exact frequencies that you want to shape your sound to each venue or song.
so your preference of a bass specific preamp or amp, still makes absolutely no sense to me.

Again, if it works for you, it works for you! Nothing wrong with that! Again, if you know what you are doing and have a pre that has at least some warmth and mid character to it, and the ability to hi pass that deep low end, you will of course be fine. I personally would rather let an expert amp designer get all that stuff together for me with the amplification of bass guitar in mind, but that's personal preference.

Again, back to OT, my main point is that the volume per watt issue has more to do with voicing than anything 'magical' with the old Acoustics.

 

[chadds]

Often the good old days are good because of selective memory. I owned a ridiculous stock 2005 300hp all wheel drive Brembo braked six-speed manual wagon.
It and it's peers could outrun 0-60 and 1/4 mile any stock muscle car of the late 60's - 70's. The added bonus was they could stop and turn really well. Great gas mileage, comfort, quiet and occupant safety complete the evolution. The one thing missing? Big drama when you hit the gas. No burnouts or giant roar!
So I don't miss the good old days of amps because when I purchased them new and gigged them I knew they could sound better. Again this IMHO, YMMV. I do know that the skillful application of tubes and hi end design can deliver any vintage to modern tone I want.

I did tolerate my 360 that we couldn't hear on stage until it was turned up to 8. Then people were dying in the back row. Above all I preferred the Sunn 2000s with two cabs 2x2x15 JBL D 140s.

I do love the discussion.

 

[truebass]

Ive had 370s, 136, 450, none of those stack up to power & pre chosen properly. I use 4-15" JBLs in big Bag End IIs with a Crown XLS 802 pre'd by a Trace Elliot GP12SMX... That said, I'm loading 2 Acoustic 406s (dual 15 ported cabs) and considering a couple new Acoustic heads. I played the 600 and it performed well.

 

[72jazzbass]

Afternoon! June 5th marked my return to an all Acoustic set up! It's been since the mid 70's, that I've had this opportunity! A 370 head, with a 406 wide cab, with the original speakers still in it! With the volume on 1, it was loud! Back when I played thru one on a regular basis, I never put it up over 2! 30+ years later, and it still smokes! Amazing!

"Nobody was ever sorry they bought the best!"

 

[duff84]

man i just got my old acoustic 150 amp head back after along time without it, im playing it tomorrow night for a gig i know its louder than my ampeg svt3pro i remember how loud these things are. i can't wait to have a nice loud clean tone again. acoustic amps rock, i think i might sell my ampeg rig and go all acoustic, will see.

 

[SanDiegoHarry]

Having lived through that era, and also somewhat regularly playing the older Acoustics that come through Low Down Sound on consignment, most of the comments are based on 'fond, wistful memories' than reality IMO and IME.
....

THANK YOU for saying it first.

This strange lust of all things old is utterly beyond me.

And yes, I owned, and gigged with an Acoustic rig for a time back in the day. It couldn't even start to compare with what I use now.

 

[lowendgenerator]

I have the privilege of playing through a 370/301 rig from time to time. It's like being hit by a sledgehammer wrapped in bison fur. Not a whole lot of definition, or tone for that matter, just straight bass and oomph! Really cool for vintage sound, not so much for anyone looking for brightness.

 

[garmenteros]

man i just got my old acoustic 150 amp head back after along time without it, im playing it tomorrow night for a gig i know its louder than my ampeg svt3pro i remember how loud these things are. i can't wait to have a nice loud clean tone again. acoustic amps rock, i think i might sell my ampeg rig and go all acoustic, will see.

They're really loud, I ended up getting the one I was being offered. 110 bucks. Theyre good amps that nail that vintage tone. Nice to have.

 

[hibbs]

I have an Acoustic 360 as a backup and I have yet to hear a solid state amp that cuts through as well. I play through your stock SVT so needless to say, it takes a dive sometimes. When it does, the Acoustic has never let me down. Midrange kills on that thing.

All that being said, they are not the loudest amps in the world. I have yet to hear anything louder (without going to complete mud) than an Ampeg SVT-CL. Just my 0.02$

 

[PDGood]

Strange - I just discovered this thread the day after comparing my old 370 to an Eden WT405. I wanted to answer the same question - what's the difference? Answer: a lot, although they both have their merits.
First I should say that I played the 370 for 35 years. I started with the folded horn, then put a Bassman on top of that, then later got rid of all of those and now run it through two Peavey cabs - each with 1-15" and a horn.
I compared it to the Eden, running each through one of the identical Peavey cabs.

Regarding volume, I've played in every kind of band there is - from glitter rock, to jazz, to show bands to country to originals and I've NEVER needed more volume than the 370 has to offer. Screw the wattage numbers, it has power like nothing else. Never got it over 10:00 o'clock, usually just above 9:00. It's a beast. The Eden seems to have plenty although I haven't taken it to a gig yet. All I can say is that with the Acoustic there is a feeling of a bottomless pit of volume that I've never felt with another amp.

Regarding tone, the biggest difference is the Eden is clearer - definition of notes is better. This is especially appreciated in the low end (E and A strings) where you can hear detail that just isn't there on the Acoustic. But the Acoustic is fuller on the G and D strings. Part of the deal is that the 370 has far better EQ - 5 band graphic that is almost entirely aimed at the lower part of the frequency range as well as Bass, Mid, Treble. So it's easy to get a nice low mid out of that amp which sounds both full and warm and may add to the fullness of the G and D. It's a beautiful tone that I love, I just wish it wasn't so mushy down low. To be fair, I never noticed it until I started comparing it to modern amps.

The 405 Eden only has three point EQ with a mid that you can choose between one of two settings (I think 200/2.2). It also has Enhance which gives the EQ scoop - reducing the mids further. But there is no way to boost the 100 to 150hz range that is so critical to bass. The 405 naturally has a very modern sound to it - pristine clean with a hint of warmth. It is warmer than a GK, but less warm than the Acoustic or a Markbass. I bought it because it is brighter and louder than the Markbass that I could afford. (Comparing used Eden to new Markbass - not really apples to apples but that was what was available in the 500-600 range).
Of course the Eden is much lighter and has a lot of bells and whistles the Acoustic doesn't - compressor, mute, and a wonderful array of inputs and outputs. And one thing I noticed - when I got the two amps EQd as much the same as possible, I noticed the low end of the EQ on the Acoustic was almost on max whereas the Eden was sitting dead flat. It had a lot more to offer there. Same is true on the highs - just more to work with on the Eden.
They both are great amps with something to offer.

 

[Gaolee]

Dude, I wish I still had my Acoustic 126. I know where it is, just don't have the $400 to buy it back.

Though it was raited at only 100 watts I can tell you that I never, ever had it turned wide open, including some outside gigs. I played with a couple of guys using 60 & 100 watt guitar amps and a drummer and could leave them all in the smoke, wheezing and begging for mercy. I can't explain the technology behind it but I can tell you I've never played another 100 watt amp that even came close!

You simply can't go wrong with them if you have the space and the back for them.

A 126 is worth $400? Hmmm.... I have had one since 1981, and it is exactly as you describe. I don't actually use it much these days, but every time I think about selling, a little voice tells me it's a bad idea. It somehow pushes a whole lot of air. I don't think it is too hard to horse around, either, what with the wheels it has. After wrestling with a 150 lb cabinet for a while, the 126 seems small and light.

I like it a lot. I also have a mid '80s B320 which I don't like near as much. Supposedly it has more power, but it doesn't have quite the same sound. This is purely subjective, but what isn't? There is more modern equipment which sounds just as good, perhaps a little different, but certainly just as good. It's all out of my price range, so I play through the old, cheap stuff which I know well enough to make sound more or less how I want it to sound.

 

[KJung]

Strange - I just discovered this thread the day after comparing my old 370 to an Eden WT405. I wanted to answer the same question - what's the difference? Answer: a lot, although they both have their merits.
First I should say that I played the 370 for 35 years. I started with the folded horn, then put a Bassman on top of that, then later got rid of all of those and now run it through two Peavey cabs - each with 1-15" and a horn.
I compared it to the Eden, running each through one of the identical Peavey cabs.

Regarding volume, I've played in every kind of band there is - from glitter rock, to jazz, to show bands to country to originals and I've NEVER needed more volume than the 370 has to offer. Screw the wattage numbers, it has power like nothing else. Never got it over 10:00 o'clock, usually just above 9:00. It's a beast. The Eden seems to have plenty although I haven't taken it to a gig yet. All I can say is that with the Acoustic there is a feeling of a bottomless pit of volume that I've never felt with another amp.

Regarding tone, the biggest difference is the Eden is clearer - definition of notes is better. This is especially appreciated in the low end (E and A strings) where you can hear detail that just isn't there on the Acoustic. But the Acoustic is fuller on the G and D strings. Part of the deal is that the 370 has far better EQ - 5 band graphic that is almost entirely aimed at the lower part of the frequency range as well as Bass, Mid, Treble. So it's easy to get a nice low mid out of that amp which sounds both full and warm and may add to the fullness of the G and D. It's a beautiful tone that I love, I just wish it wasn't so mushy down low. To be fair, I never noticed it until I started comparing it to modern amps.

The 405 Eden only has three point EQ with a mid that you can choose between one of two settings (I think 200/2.2). It also has Enhance which gives the EQ scoop - reducing the mids further. But there is no way to boost the 100 to 150hz range that is so critical to bass. The 405 naturally has a very modern sound to it - pristine clean with a hint of warmth. It is warmer than a GK, but less warm than the Acoustic or a Markbass. I bought it because it is brighter and louder than the Markbass that I could afford. (Comparing used Eden to new Markbass - not really apples to apples but that was what was available in the 500-600 range).
Of course the Eden is much lighter and has a lot of bells and whistles the Acoustic doesn't - compressor, mute, and a wonderful array of inputs and outputs. And one thing I noticed - when I got the two amps EQd as much the same as possible, I noticed the low end of the EQ on the Acoustic was almost on max whereas the Eden was sitting dead flat. It had a lot more to offer there. Same is true on the highs - just more to work with on the Eden.
They both are great amps with something to offer.

Nice post. A couple of things. Your comment about having to turn the bass control up almost all the way to match the typical voicing of a more modern solid state amp is right on, and is what I was trying to communicate in my previous posts. And, guess what happens to the 'amazing headroom' that some talk about with the old acoustic amps when you dial in that missing low bass Again, very easy to make an amp loud with relatively low wattage when the deep low end is rolled off and the midrange has a lot of distortion built in (I assume due to limitations in these early solid state components). That being said, it is a cool tone for what it is.

And secondly, the physical position of the master volume knob means nothing. Many amps can easily reach their full output with the master volume well below noon, depending on how hot the input signal is, and the taper design of the volume pot. Manufacturers play this game all the time, making the master volume taper very linear, which results in big jumps in volume (which is nonlinear) at quite low levels.

Again, no magic, just voicing, distortion levels and master volume pot design. Nice heads for their time, and they still sound good if that sort of voicing is your thing.

 

[banikek]

My experience with ACC stuff is slightly different than others on here. I currently own the 360 and 370 and gig with them regularly. I have owned the 301 cab and the Acoustic 2x15 cabs and hated them! Way too boomy and muddy. I find that if use some of the more modern speakers I can dial in some sweet sounds.

This rig sounds damn nice. 360 with a 300 power amp and 2 GK 410T cabinets.

chris