Topic: audiophile

[bucky katt]

not if you wire them in series i dont think

[TwoTired]

mlinder, BobbyR,  I think we have chronic agreement on most points.

I have an old Kustom 100 with 4 10s, I have a 57 Fender Twin, and a 68 Fender twin reverb with 2 JBL 12s.

The Kustom is clean at low volumes and dirty at higher volumes.
Same can be said for the 57 Fender twin.  They are both freaking loud when they start to color the guitar sound.  They give me headaches.

The 68 Fender Twin reverb is very clean and doesn't add any color til the volume knob is at 9.5.  ( I don't have "11" knobs on it.)    It is physically fatiguing at that volume, even with earplugs.  No one wants to stand in front of that thing at that setting, as you won't have any high frequency hearing for about 3 days after the experience.  Then you will wonder why all your adjustments on everything you've been listening to are set for such a bright augmentation.

At home, which is the only venue I play these days, I use a PA stereo amp, and mixing board, and have several sound modeling/shaping instruments to get ANY sound I want from the guitar, so the amp only amplifies (cleanly) whatever is fed to it.   I still get the overtones, harmonics, and sound "feel" I get with those other amps turned up to "dirty, crunchy", etc, with whatever volume I wish at the time.  It''s not all that portable, though.

Still, life is good.

The real point I was trying to relay was that most >guitar< amps are NOT suited for audiophile music reproduction use.

Cheers,

[TwoTired]

man, I'm in over my head here. 

OK, my old 30 watt Amp sounds quite good with the 4 ohm speakers I'm using now.
I have four wired in. Do you think this is going to hurt my amp since it was designed for
8 ohm speakers?

Kinda depends on the output stage design.  Some of the old units used transistors that needed a certain load or range of loads to survive.  Other types survive well with impedance mismatches on their output.  However, they won't meet distortion specs with an impedance load outside specified parameters.

Are you saying you have one 4 ohm speaker connected to an output labeled 8 ohms?  Are you operating at high volumes?

[BobbyR]

mlinder, BobbyR,  I think we have chronic agreement on most points.

I have an old Kustom 100 with 4 10s, I have a 57 Fender Twin, and a 68 Fender twin reverb with 2 JBL 12s.

The Kustom is clean at low volumes and dirty at higher volumes.
Same can be said for the 57 Fender twin.  They are both freaking loud when they start to color the guitar sound.  They give me headaches.

The 68 Fender Twin reverb is very clean and doesn't add any color til the volume knob is at 9.5.  ( I don't have "11" knobs on it.)    It is physically fatiguing at that volume, even with earplugs.  No one wants to stand in front of that thing at that setting, as you won't have any high frequency hearing for about 3 days after the experience.  Then you will wonder why all your adjustments on everything you've been listening to are set for such a bright augmentation.

At home, which is the only venue I play these days, I use a PA stereo amp, and mixing board, and have several sound modeling/shaping instruments to get ANY sound I want from the guitar, so the amp only amplifies (cleanly) whatever is fed to it.   I still get the overtones, harmonics, and sound "feel" I get with those other amps turned up to "dirty, crunchy", etc, with whatever volume I wish at the time.  It''s not all that portable, though.

Still, life is good.

The real point I was trying to relay was that most >guitar< amps are NOT suited for audiophile music reproduction use.

Cheers,

Exactly. I have a set of McIntosh 30W Monoblocs with matching tuner and preamp. These cannot possibly drive my   Bozaks. So, people see the nice tubes all lit up pretty. What they do not see is the 200 watt Hafler the preamp is actually feeding. The tube sound of the preamp is picked up and faithfully reproduced by the larger amp.

[BobbyR]

man, I'm in over my head here. 

OK, my old 30 watt Amp sounds quite good with the 4 ohm speakers I'm using now.
I have four wired in. Do you think this is going to hurt my amp since it was designed for
8 ohm speakers?

The main question is, how long have you been running this setup? If the answer is a years, the answer is no. Whatever was going to pop would have popped. Transistors unlike tubes are not very forgiving. The other equally important question is, do you like it? If you do, rock on! My daily listener is a simple Tivoli one table radio. I crank the other stuff for company.

[bucky katt]

can you use those great huge live power amps for home stereo use? i would imagine using more power at a lower setting would give clearer sound at the same level as a smalller amp being driven harder. something like this http://pro-audio.musiciansfriend.com/product?sku=481587V

[mlinder]

can you use those great huge live power amps for home stereo use? i would imagine using more power at a lower setting would give clearer sound at the same level as a smalller amp being driven harder. something like this http://pro-audio.musiciansfriend.com/product?sku=481587V

Look at the THD between that, and something like, say a Harmon Kardon.
http://harmankardon.com/product_detail.aspx?cat=REC&prod=AVR+347

[bucky katt]

yikes..............guess not eh?

[mlinder]

RIght-o.
That's not to say there aren't power amps that are similar strictly for home and studio use that have very good sound.
But those kinds of power amps you linked to are made for another purpose. Usually, live situations, where there are many of those bastards pile don top of each other pushing sound to a crap ton of speaker cabinets.
There are all kinds of concessions made in their design for the sake of durability, cost effectiveness, predictable output, and the demands of large areas with, usually, pretty #$%*ty accoustic properties to begin with.

[TwoTired]

There are certainly some that would argue that few could discern the difference between a unit with .5% and another with .07% THD.
There are some golden ears out there that say they can.  Maybe I could at one time in the past.  Today, I'd need test equipment.

If a gnat lands on your ear can you tell if it has 20 hairs on it's butt or 200?

Another thing to consider with those specs is that the rating's apply to full rated output power.
Sure the Crown has .5% THD at 2,100W. Vs, the Harmon Kardon's 0.07% THD @ 665W.
But, we don't know what THD spec the Crown has when only pushed to 665W output.  It *could* be 10 times better.  Then again, if neither unit comes anywhere near being taxed, the THD *could* be far better than spec in both cases.  It's unlikely your hearing would last long intact sitting a small room with 665W of program material pumped into it. (Which might be a blessing if the program material was a Juice harp concerto of Yoko Ono's greatest hits.    )

Anyway, that's the problem with spec comparisons.  You need tests under similar conditions to get meaningful comparisons.

Cheers,

[Rocking-M]

The sound is pretty good, I don't really crank it that high. Only been running it
about a week.

The speakers I'm running now are wired in on the A circuit and the B circuit then
I run A/B together. Someone give me the basics on wiring in series versus parallel.
I'd like to wire in one more set of speakers out on the porch over the porch table.

[Markcb750]

It has been my experience that the best place to spend big $$ on is speakers. 

Speakers have distortion numbers that can be much greater then any amplifier, and speakers that produce the required sound pressure level with low power input, (efficiency) and without inducing amplifier clipping or reflected noise are much more effective at improving reproduction.

[BobbyR]

The sound is pretty good, I don't really crank it that high. Only been running it
about a week.

The speakers I'm running now are wired in on the A circuit and the B circuit then
I run A/B together. Someone give me the basics on wiring in series versus parallel.
I'd like to wire in one more set of speakers out on the porch over the porch table.

I wanted to do the same thing. I toyed with using switches. I simply took a cheap but decent receiver I picked up in my ebay shopping and a couple of speakers and put the whole thing on the back deck. this way I did not have to go in the house to turn it on and off and adjust the volume. I throw a garbage bag over it to protect it form rain. They last 4-5 years. Works for me.

[mlinder]

Hey TT.

Yeah, without a graph on output at all levels on all frequencies, it's hard to tell just from 'specs'.
But, and I'm sure you might know this, with being a musician, I've heard many power amps being used in many different settings, and there's something about the big power amps used for clubs, etc, that just sounds different, and incorrect, for straigth listening to recorded music in your home or studio.
There is, almost invariably, some frequency cutoffs, dips, and peaks that seem to be hardwired into nearly every 'club' or musical instrument power amplifier. I can hear it, and while my hearing is no longer perfect, it's still pretty good.
For some reason, their seems ot be spikes in the 60-100hz range on them, as well as about 900hz to 4.5khz, with large drop offs at about 12khz and up, as well as below about 50hz. Varies form company to company, but the variables are are pretty minor.

[TwoTired]

But, and I'm sure you might know this, with being a musician, I've heard many power amps being used in many different settings, and there's something about the big power amps used for clubs, etc, that just sounds different, and incorrect, for straigth listening to recorded music in your home or studio.

Hey M,
I think I know what you are referring to.  But, are you really noting amp characteristics or room acoustics, with perhaps a bit of speaker characteristics thrown in?

Back in the day, we used to use a room frequency analyzer to adjust the equalizer on the PA amp.  You'd hook up a white noise generator to an input, then walk the room with a portable frequency analyzer making notes as to spikes or dips that were characteristic of the room/speakers/amp combo.  Then you went back to the equalizer and made adjustments to get a flat response curve for the venue, speakers, and amp combined.  It was a good first cut to get the sound right for the room.  Wasn't perfect, though, as once the room filled with people, the room acoustics changed because bodies absorb sound waves.  High ceiling venues were usually more stable, provided the speakers were also up high.  You really needed a sound engineer to be in the room for ongoing tweaks during the set.  If you want your stage equipment to reach well into the room, make sure those speakers are above crowd level, too.  Better yet is an elevated stage.  Of course, that can be bad for musician ears.

Further, multiple and large speaker systems are just harder to drive accurately and keep them all in phase unison.  Higher power seems to help that.  Speaker placement within a room can also be a factor.  But, the extreme accuracy that occurs when the same high power amp is used through a low load speaker system just sounds...different. Heh...how's that for tech talk? 

I have to ask, though.  Are you using a CD or digital source for your comparison experiment, or an analog source for the sound quality comparison?  And, were both systems equalized for the venue?

Cheers,

[mlinder]

There were various times I've noted a difference.
Most notably were in recording studios. Different amp through same studio monitors in a control room.
Once was just analog reel to reel 24 track, once was a mix of analog 16 track for drums synched to a bank of adats for all other instruments.
Another time one was home use, had a friend using a carvin power amp for home speakers. He had a HK that was far less powerful, but really noted a difference in sound quality between the two, through a fairly nice set of JBL's.
I didn't go so far as to set up a freq analyzer, was just going by ear, in the above situations. Having done this crap for as long as I have, I have a pretty good ear for frequencies, but it's certainly not 'scientific'.
There's just something weird about the output of the instrument/pa amps.

[BobbyR]

And alas poor Robert from Virginia who has a real need to know how to configure his nice little component system is left in the dust.

[TwoTired]

And alas poor Robert from Virginia who has a real need to know how to configure his nice little component system is left in the dust.

Fine.  I'll shut up then and wait for someone with a schematic or service manual to post info on his amp.

[mlinder]

I can't find a schematic for it online

[BobbyR]

And alas poor Robert from Virginia who has a real need to know how to configure his nice little component system is left in the dust.

Fine.  I'll shut up then and wait for someone with a schematic or service manual to post info on his amp.

No offense meant, this has been great, it is just sometimes we all drift into very interesting places and the original question gets lost.

[Duke McDukiedook]

man, I'm in over my head here. 

OK, my old 30 watt Amp sounds quite good with the 4 ohm speakers I'm using now.
I have four wired in. Do you think this is going to hurt my amp since it was designed for
8 ohm speakers?

It could if you really crank it, if you listen at normal volume levels most of the time, it shouldn't do any damage.
The only way you will truly know if you are doing/did damage is if you start blowing fuses/output transformers.

[Rocking-M]

Hey BobbyR, I gets left in the dust a lot. 

a real basic question, if I take two 4 ohm speakers and wire them
in series or is it parallel, will I have 8 ohms of impedance?   

[TwoTired]

Resistance adds in series.  4 ohm in line with 4 ohm yields 8 ohms.  4 ohm in parallel with 4 ohm yields 2 ohm, FYI.

I couldn't find an on line source for a schematic or service manual for your amp without paying $14.95.

[BobbyR]

Resistance adds in series.  4 ohm in line with 4 ohm yields 8 ohms.  4 ohm in parallel with 4 ohm yields 2 ohm, FYI.

I couldn't find an on line source for a schematic or service manual for your amp without paying $14.95.

There is your answer. What i could find about your Amp is that it can handle 4 or 8 ohm, so you should be fine as you are. Enjoy your sound.

Now, about these Guitar Amps. I read some articles years ago that to use an audio tube amp for a Guitar would entail some significant rewiring to work properly. It seems an Amp is not simply an Amp.

[ofreen]

I'll veer back to stereo amps for a second.  I am still running my old Phase Linear 400 I bought in 1974.  They come up on Ebay occasionally, as well as the model 700.  Fewer and fewer these days, though, because they have been rediscovered.  Very interesting solid state amps, designed by Bob Carver.  Rocking-M, they have the analog VU meters you crave, good specs even by today's standards, and they kick ass.