Hi-Fi driver .vs. Instrument Driver

Hi,

I have been reading a bit and planning to build a Guitar amp for my son.

One thing that seems to come up a bit is driver selection and people wanting to use Hi-Fi type drivers for their guitar amp. I am also in this position - I have a couple of old 12" drivers that I thought might be OK to get started with and then upgrade later - but I now think this is wrong.

But, is using Hi-Fi drivers such a problem if I am building a chip based amp rather than tube? I am starting to understand how electric guitar is all about distortion etc. But, if I am building something from runoffgroove or tonepad as a pre and feeding that through a LM3886 isn't all the distortion being simulated in the pre? Therefore, shouldn't the power amp and the driver reproduce the signal from the pre-amp and a pretty linear manner??

If so, then wouldn't a Hi-Fi driver (and even a Hi-Fi tuned cab) be more appropriate?

Thanks,

Brian
 
You can do it that way because with many of hte modern effects devices, the distortion sounds are indeed generated inside the device. There is a big difference however between simulated distortion and real distortion. Some of the new solid state devices do a decent job of it but still, I haven't yet heard one that I could live with. You really do need tubes to generate the distortion and you need low powered speakers designed for guitar to add to the distortion. If you try to get these sounds out of hi-fi equipment, it always sounds bad because hifi equipment is designed not to distort. So, when you force it to distort, it does so in a distasteful way. Equipment that is built for guitar is designed with the distortion factored in right from the beginning and so when it does its thing, it sounds great.

I highly recommend you investigate some of the tube amp projects such as the AX84 site or www.18watt.com (which is obviously my favourite. Or at least it will become obvious if you check out my site.) :D

I also hold strongly to the belief that it is far more important to have a great amp and a good guitar than a great guitar through a merely good amp. I can play a cheap guitar as long as it is through a great amp. The sound will be great. If I play a $10,000 guitar through a cheap amp it will sound awful.

HTH
 

38eighteen

Member
2007-11-08 9:18 am
sreten said:
...12" attempting full range

Ah yes, this is the bit I had lost sight of when I decided to post my question - the 12" drivers I have are from 3-way speakers. They are not (I assume) anywhere near full-range.

I know there is another thread about what range a guitar produces - I'm off to re-read that.

I have been experimenting with some software called ARTA so I also plan to try to measure the range of my 12". I don't expect to be able to use them - it will be a learning exercise.

Thanks,

Brian
 
38eighteen said:


Ah yes, this is the bit I had lost sight of when I decided to post my question - the 12" drivers I have are from 3-way speakers. They are not (I assume) anywhere near full-range.

I know there is another thread about what range a guitar produces - I'm off to re-read that.

I have been experimenting with some software called ARTA so I also plan to try to measure the range of my 12". I don't expect to be able to use them - it will be a learning exercise.

Thanks,

Brian


Hi. Brian,
All electric guitars, especially lead or rhythm need adequate amp/speaker to produce unique sound and dynamic. In my experience, speaker is most important. In rebut, you will lost some needed harmonics or boost some unneeded. For example: you will get better guitar sound if you connect bad hi-fi amp to good guitar cabinet, rather then best guitar amp to best hi-fi box. Maybe some full range driver can work enough good, but much better solution is purchasing one or more 8, 10 or 12" guitar driver. Very good choice is Celestion or Eminence Legend guitar series.

Second thing is guitar amp. Tubes makes really good guitar sound. For me, preamp with tubes like Marshall, Fender or similar produce 80% of desired sound. Tube power amp will work better, but solid state or chip based amp also be very good in combination with tubes.

Like Graydon say, difference between simulated distortion and 'natural' amp overdrive is big. I have been try some guitar processors, but nothing make me happy like small tube amp at maximum gain.

That is my opinion, but your ears or ears your son is judge.

Oly :eguitar:
 
Thanks for all the advice.

Here is my updated plan (sorry, I seem to have combined this with my "Please review my guitar amp plan" thread):
- Build a nice combo box
- Build the runoffgroove.com Thor (that I have already ordered parts for) as a pre-amp
- Build the 2 x LM3875 kit that I have in my drawer as the power amp
- Buy new drivers
- Wait for my son's tastes to "mature" :) and do some more research and learning and replace Thor with a nice tube pre-amp one day.

The LM3875 is rated at 56W and I have a 300VA toroid so they should be able to deliver.

My new question is - what driver(s) should I get? I was initially thinking 2 x 12" because I was going to use the ones I had to start with but now that you have convinced me not to bother my choice is only limited by practicality, money and what I can get in Australia.

I have been searching for Celestion or Eminence Legend in Australia most of the afternoon (off and on...) and can only seem to find speakers with these drivers of used ones on eBay. A couple of Legend 105s would seem to be a good match to my proposed power amps and fits my budget but I can't seem to find them in AU. I know I can buy from the US and have them shipped, but I'd like to try local if I can.

Thanks,

Brian
 

Brett

Member
2002-01-07 6:02 pm
38eighteen said:
...or, is 112W just silly overkill for a 13 year old who jams with his mates and plays in the Church band? Should I use my LM3875 kits for the nice Hi-Fi amp I bought them for and build my son something based on LM1875??? Argghhh choices, choice....

Thanks,

Brian
100W, even SS through guitar speakers is bloody loud. Maybe the 1875's are a better idea, or just one 3875.

Eminence are distributed through Music Connection in Adelaide, but they're pricey. Evatco have some Jensen's, but secondhand off ebay is probably the cheapest. However, if you decide to import let me know via PM as I have some good sources and we may be able to combine shipping and maybe save some money.
 
sreten said:
TBH I would simply look for a decent secondhand guitar combo
with reverb, probably a 30w to 50w 1x10 or 1x12 would be fine.
The Thor I'd build as a stomp box as intended.

Yeah, I know that makes most sense. I have been looking and have been amazed how cheap you can get stuff.

But, this is diyaudio.com. I'm here because I am looking for an excuse to build something, not to be practical. :D

Thanks,

Brian
 
That 100W SS amp will probably be adequate. My 18W tube amps will be much more punchy, will go into distortion more smoothly and sound better doing it. There is something about hi-fi SS amps that requires at least ten times the power to match up to a tube amp. I have a Roland JC120 which is 60wpc SS and it is good but in a totally different way. It also is tweaked to work for guitar, having much more midrange than a typical hifi amp. I still prefer a good 18W tube amp any day over any SS amp I have ever tried.

You can make it work, but you have to approach it from the guitar rather than from "sound reinforcement."
 
If you are planning to use the Thor as a preamp be sure to add a tone control similar to what was done with the Thundercheif on Runoffgroove.com You should be able to wire it in before the opamp. I tried using the Thor and an LM4780 as an amp just a few days ago and found the sound was fairly good, but needed more tone control. Also it was not easy to get a good clean sound, but the distortion was pretty good.

Oh and one of your LM3875's will be plenty lour, I would consider uing the LM1875 you mentioned, especially if you get your hands on a real MI speaker.

G.
 
Brett said:
100W, even SS through guitar speakers is bloody loud. Maybe the 1875's are a better idea, or just one 3875.

Eminence are distributed through Music Connection in Adelaide, but they're pricey. Evatco have some Jensen's, but secondhand off ebay is probably the cheapest. However, if you decide to import let me know via PM as I have some good sources and we may be able to combine shipping and maybe save some money.


Absolutely right Brett !

Brian, if you like your son and yourself, don't make amp with power more then 15-30w. Practice and home/small clubs playing is one thing, Deep Purple concert under open sky is second. Most of guitar speakers have big sensitivity and you no need too much of power. I can recommend to you two Celestion G12H, G12M (Greenback) or similar speakers which sounds great for most guitar sound styles.

You can looking for GainClone threads for power amp solution. Power supply with +/- 20v for lm3875 is enough. It's about 30w output. Some tricks: don't use capacitors larger then 2200uF and put one resistor 0.47E in series between output and speaker. This will produce more 'tube' sound.

Marshall tube preamp (Master volume type like 2203) with adequate attenuator on output will make "beast" sound. Of course, you must build and proper power supply for it...

Just run man! ;)
 
In my opinion, the very finest guitar speaker is the Electrovoice EVM-12L.

For a while, back in the 80s, Mesa (of Boogie amplifier fame)were selling what I guess, without much evidence, was an OEM version derived from it called the "Black Shadow", very cheaply. If you can find one of those in decent working order, it offered amazing value for money.
 
While searching for Celestion drivers in Australia I came across this: http://www.melmusic.com.au/shop/index.php?productID=10139

[email protected] seems interesting for $AU142 shipped. Anyone care to comment?

The best (so far) I can find a real Celestion (25W) G12M for $AU215 shipped.

I know it is not a huge difference, but considering the use this is going to get I will probably go with the clone unless someone has a specific bad story to tell about them.

Thanks,

Brian
 

Brett

Member
2002-01-07 6:02 pm
PigletsDad said:
In my opinion, the very finest guitar speaker is the Electrovoice EVM-12L.

For a while, back in the 80s, Mesa (of Boogie amplifier fame)were selling what I guess, without much evidence, was an OEM version derived from it called the "Black Shadow", very cheaply. If you can find one of those in decent working order, it offered amazing value for money.
Quiet. Don't want everyone to know. The last combo I built for a customer was a tube 18W Harp amp with a pair of EVM12L. Sounded incredible. Cuts through the mix like a lightsaber but not harsh and has dynamics and nuance like nothing else. Original plan was EVM10's but he lucked on these so I used them. Sound good as hifi drivers 150-800 too.

Brian, I have heard good things about the Lorantzes, but have no first hand experience. If you can wait a bit, check out the post Xmas ebay auctions which often yield all sorts of bargains.
 
I like EVM12Ls for guitar but they are too heavy and I also find they lack upper frequency sparkle. The midrange is a little too strong too. That works with a Fender-style amp because the Fender blackface designs have a slight scoop in the midrange. EVMs do not work with Marshall designs because Marshalls typically have a strong midrange already. The EVM just makes that worse. Now, the older EV, the SRO is much like the EVM except it has an alnico magnet (and not quite as much power handling) and that SRO sounds really nice. I still kick myself for selling a minty pair of those a few years ago.

I like Jensens for Fender amps and Celestions for Marshall amps. It doesn't matter too much which Celestion. They all work well(with a couple noted exceptinos - I don't care for the G12T75 - it is lifeless IMHO.)

Speaker choice is a fun journey.