Bugle and ELP Laser Turntable

vanmeter · « **on:** 6 Mar 2007, 12:47 pm »

I have had the Bugle a while and really like it. About 6 months ago I took the plunge and bought an ELP laser turntable, which I'm generally happy with. I have problems, though, with rock and other records cut "hot", especially on hi-hats and "s" sounds...like sibilance only a little more steely, slushy and distorted. Most jazz and classical sounds as good as I've ever heard it, but, again, the louder the disc is cut the more trouble I have.

I had just decided that this was a limitation of the ELP, and it may be, but I thought I should ask; since the Bugle isn't a standard feedback circuit, is there any chance that the ELP could be overloading something in the Bugle? I'm guessing the true test would be trying it with a tube preamp, but I don't have access to one, and if I run the ELP into a mic preamp it distorts there as well, but differently, which could either be just the effect of not hearing the RIAA curve or a different overloading distortion, if that's what it is.

Thoughts? Thanks!

hagtech · « **Reply #1 on:** 7 Mar 2007, 03:56 am »

Sorry, I don't know anything about the ELP. Doesn't it have a built-in phonostage?

jh

vanmeter · « **Reply #2 on:** 7 Mar 2007, 12:40 pm »

It does come with that as an option, but mine just runs into any phono stage.

Here's a clip; this distortion on the word "situation" is pretty typical on 80s pop and rock records that are cut with a lot of top end...but this also shows up on anything from any era during really hot treble peaks, which is why I was just curious if it might be overloading something somehow when the record is cut really hot. Again, it might be something internal on the ELP overloading, I realize. Just wondering what the possibilites are.

http://www.geocities.com/vanmeterannie/07.mp3

jeffreybehr · « **Reply #3 on:** 7 Mar 2007, 05:12 pm »

"...mine just runs into any preamp".

Do you mean any phono stage or any line stage?

vanmeter · « **Reply #4 on:** 7 Mar 2007, 05:31 pm »

Sorry; yes, phono stage. It does not have a built in phono stage and does not have a line level output.

hagtech · « **Reply #5 on:** 7 Mar 2007, 06:59 pm »

It sounds like overload. What is the output level from the ELP?

jh

vanmeter · « **Reply #6 on:** 7 Mar 2007, 07:24 pm »

This is from their website; I can check the actual manual later and let you know if it's different, if it matters:

4.3mVrms 5cm/s 1kHz Lateral
9.7mVrms 8cm/s 1kHz 45° Left or Right modulation
11.3cm/s 1kHz Lateral (much like MM cartridge)

G.ear · « **Reply #7 on:** 7 Mar 2007, 07:57 pm »

Hi Vanmeter,

I own an ELP laser table as well. Sorry to say I don't know what a Bugle is, but I'm with Hagtech in that it sounds like overload to me as well. The output from the laser table is too high given the amount of gain present in most phono stages, so you could be overloading either the phono stage or the line stage, but most likely overloading the input to the line stage. I have two different line stages, an H-Cat and a Herron VTSP-2. I have problems with overload into the H-Cat (solid state), but not into the Herron (tube).

Dean

vanmeter · « **Reply #8 on:** 7 Mar 2007, 08:48 pm »

Wow, thanks for the input. I had hoped that was the case, since that's my main complaint about the ELP. I'll try a couple of different things - reducing the gain in the Bugle wouldn't help, I'm guessing - but it sounds like I might need to look at tubes in my future.

vanmeter · « **Reply #9 on:** 7 Mar 2007, 11:13 pm »

Okay...I tried going directly into my soundcard from the Bugle...same thing. I tried the Bugle directly into my NAD preamp...same thing. I also got essentially the same results with the Bugle into my old Fender guitar amp, the only thing tube I have working at the moment. I also ran it into the phono stage in the NAD and it distorts there as well, though, so could I conclude that the ELP's output is high enough to distort anything solid state?

hagtech · « **Reply #10 on:** 7 Mar 2007, 11:55 pm »

First, let's make sure we're not running two phonostage in series. What is the gain of your Bugle? From the specs listed, the 40dB version should be able to handle it no problem without anywhere near overloading. I wonder if the ELP provides EQ correction already?

jh

vanmeter · « **Reply #11 on:** 8 Mar 2007, 12:01 am »

The Bugle is at 40db, yes, and there's no EQ built into the ELP. They sell a version with an internal phonostage, but that's not what I have.

G.ear · « **Reply #12 on:** 8 Mar 2007, 10:40 am »

Vanmeter, it's impossible for me to say if what you are hearing is overload, and equally impossible to know if all solid state preamps would experience overload when driven by the ELP. However, in this age of relatively low output moving coil cartridges, most phono stages are designed with fairly high gain. My own phono stage has 42 db of gain and it isn't really intended to be moving coil compatible.

I'm no mathematician (as I'm about to demonstrate), but my understanding is that for every 3 db of gain, you double the voltage. If that is correct, and you are experiencing a 4.3 millivolt output from the ELP into 42 db of gain, you would double that 4.3 millivolts 14 times which I believe is to say taking it to the 14th power. I may be mistaken about this, so please consult with someone with some expertise on this point, but if I am right, you'd have about 70+ volts going into the line stage. Now that's scary!! There is probably something all wrong with my thinking on this point because it doesn't make any sense that the ELP would be designed in such a manner. Hopefully, someone else will chime in here who can do the math.

You might want to send ELP an e-mail and ask them about the phono stage gain specs. needed for compatability.

Dean

vanmeter · « **Reply #13 on:** 8 Mar 2007, 12:46 pm »

What is your phono stage you are running your ELP into? Tubes?

samplesj · « **Reply #14 on:** 8 Mar 2007, 02:34 pm »

Quote from: G.ear on 8 Mar 2007, 10:40 am

Vanmeter, it's impossible for me to say if what you are hearing is overload, and equally impossible to know if all solid state preamps would experience overload when driven by the ELP. However, in this age of relatively low output moving coil cartridges, most phono stages are designed with fairly high gain. My own phono stage has 42 db of gain and it isn't really intended to be moving coil compatible.

I'm no mathematician (as I'm about to demonstrate), but my understanding is that for every 3 db of gain, you double the voltage. If that is correct, and you are experiencing a 4.3 millivolt output from the ELP into 42 db of gain, you would double that 4.3 millivolts 14 times which I believe is to say taking it to the 14th power. I may be mistaken about this, so please consult with someone with some expertise on this point, but if I am right, you'd have about 70+ volts going into the line stage. Now that's scary!! There is probably something all wrong with my thinking on this point because it doesn't make any sense that the ELP would be designed in such a manner. Hopefully, someone else will chime in here who can do the math.

You might want to send ELP an e-mail and ask them about the phono stage gain specs. needed for compatability.

Dean

No, not exactly. The rule of thumb you are talking about is that for every doubling of wattage you get 3db of acoustic output gain. This is voltage gain and not wattage so we use the 20 instead of 10 [20 * log(Vnew/Vold) = gain]. Since its 20 instead of the 10 for wattage we need to double the rules of thumb - 3db = 2x and 10db = 10x to 6db = 2x and 20db = 10x. This means its really close to 2^7 not 2^14 so its only like 128x not 1684x. This means its only like 0.5v and when most cd players/dac put out 2.0v I'd not think 0.5 is causing a problem.

vanmeter · « **Reply #15 on:** 8 Mar 2007, 02:45 pm »

And again, it could be something inherent in the ELP itself. I asked the company about this and they basically said that records with a lot of treble information could cause this to happen, but I'm just not clear if it's coming out of the player distorted before it ever hits the phono stage or if it's just overloading something in the phono stage with it's strength. If Dean is able to get his to play without distortion, though, that's encouraging to me.

analog97 · « **Reply #16 on:** 8 Mar 2007, 03:08 pm »

I am puzzled. The ELP is different. It uses some kind of laser-reading to extract info from the LP's grooves. The STEREOPHILE review said that the ELP is fundamentally "analog". I don't get it. I am wondering when that laser tries to "read" high-frequency, small jagged LP grooves that something happens to cause some of the symptoms you report. I am most curious to hear an ELP and find out what all the fuss is about. Without hearing it, I am from Missouri. You don't happen to live in Pittsburgh, PA do you?

vanmeter · « **Reply #17 on:** 8 Mar 2007, 03:13 pm »

No, sorry, I don't. I could post some more examples of this distortion if it would lead to more insight.

analog97 · « **Reply #18 on:** 8 Mar 2007, 04:51 pm »

Sounds to me that the high-frequency laser "reading" causes short duration voltage spikes in output. You will need an engineer to figure this out.

vanmeter · « **Reply #19 on:** 8 Mar 2007, 05:06 pm »

Actually, it just occured to me to run the ELP directly into the Fender tube amp I have, and the distortion is apparent there without the RIAA curve and gain, so it must be coming from the ELP itself, sad to say.