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Shift-line Olympic Pre/Crown 1502 problems
- Thread starter lala
- Start date
The Olympic MkIIIS specs say the 1/4" output can produce 20dB. I believe this is 20dBu-- 7.75V RMS.
The input sensitivity for the 1502 is switchable. Choices are 0.775V RMS or 1.4V RMS.
AFAIK 0.775V = 0dBu and 1.4V = 5.14dBu. So if you have the MkIIIS it should easily drive the amp to full power. Try toggling the sensitivity setting on the amp to High.
One possible problem is the 1/4" out is unbalanced. If you are using a 1/4 TS to XLR adapter, I believe you loose 6dB and the adapter must be wired in a way the is compatible with the amp...(adapters can be wired different ways).
The input sensitivity for the 1502 is switchable. Choices are 0.775V RMS or 1.4V RMS.
AFAIK 0.775V = 0dBu and 1.4V = 5.14dBu. So if you have the MkIIIS it should easily drive the amp to full power. Try toggling the sensitivity setting on the amp to High.
One possible problem is the 1/4" out is unbalanced. If you are using a 1/4 TS to XLR adapter, I believe you loose 6dB and the adapter must be wired in a way the is compatible with the amp...(adapters can be wired different ways).
Thx. I have been on the phone with Crown for days, and that has been helpful. Yes. I have already changed the sensitivity on the Crown to 0.775, and it did make a slight difference. But still, with any of my passive basses plugged into the Olympic, bass volume cranked, and even with both the volume and gain controls on the Olympic cranked, it's still nowhere near what my Kemper achieves, nor my Hotone Ampero Stomp. With the Olympic cranked as described, and the Crowns volume set as high as 5 O'clock, the Crowns DB meter cannot achieve any level higher than the -40 db mark. Last night I did a test. I measured my bass's level at the end of its instrument cable, with its volume cranked and slapping hard all strings, to find out how much voltage output is organic to the bass. It was about 0.090 V. Then I output a 1khz sine wave from my iPhone, and measuring the output from the phone, set it at the same level as the cranked bass, 0.090. I then plugged the iPhone into the Olympic's instrument input, and using the sine wave, measured the output voltage at the balanced out, volume and gain cranked on the Olympic. I measured from the ground and positive xlr pins. I also measured the unbalanced out, measuring the end a TS cable. My measurements show an output voltage of around 0.600 V, which is well below what would be required to drive the Crown to full power. One other thing to note is that the Olympic spec indicates 1k ohm impedence at the balanced out. Crown says that could also be the issue.
Also of interest is that while measuring the output voltage of the Olympic using the sine wave, if I cranked the treble and toggle to Top Boost, voltage output almost doubles. So, not sure where to go from here. I personally think that the Olympic does not output the levels it claims to. If anybody out there has the same setup and is achieving a different actual result, I would love to know. Someone who is using the Olympic-power amp- 8 ohm cabinet chain.
So, yes, I know what the Olympic specs say, but in fact, regardless of my measurements, with everything cranked, the Crown VU meter doesn't even get to -20, and the audio level doesn't nearly reach what it should. With the Crown in bridge mode, sensitivity setting at it most sensitive, bass cranked, I should be rattling the windows as I have with the Kemper. With the Olympic I get a fairly loud living room level. With the Kemper, a coffee house level.
Also of interest is that while measuring the output voltage of the Olympic using the sine wave, if I cranked the treble and toggle to Top Boost, voltage output almost doubles. So, not sure where to go from here. I personally think that the Olympic does not output the levels it claims to. If anybody out there has the same setup and is achieving a different actual result, I would love to know. Someone who is using the Olympic-power amp- 8 ohm cabinet chain.
So, yes, I know what the Olympic specs say, but in fact, regardless of my measurements, with everything cranked, the Crown VU meter doesn't even get to -20, and the audio level doesn't nearly reach what it should. With the Crown in bridge mode, sensitivity setting at it most sensitive, bass cranked, I should be rattling the windows as I have with the Kemper. With the Olympic I get a fairly loud living room level. With the Kemper, a coffee house level.
BTW, these sort of problems frustrate me quickly, as I don't have loads of time or patience. So, while I/we try to figure out the Olympic issue, I just ordered a Mesa Boogie TT-800. It should be here tomorrow, and I look forward to the plug'n'play nature of a good ol' amp head.
The XLR out is rated for 10dB, which AFAIK should still be plenty.
I am not following why the 1Kohm output impedance would be a problem. Normally you want impedance bridging, so ideally the amp's input impedance should be 10k or more. Per the specs the input impedance for the 1502 is 20k balanced and 10k unbalanced.
Have you contacted Shift Line?
I am not following why the 1Kohm output impedance would be a problem. Normally you want impedance bridging, so ideally the amp's input impedance should be 10k or more. Per the specs the input impedance for the 1502 is 20k balanced and 10k unbalanced.
Have you contacted Shift Line?
Oh yes.
Many emails with Shiftline. They have been nice, and have encouraged my testing. You state the 10db output, but Crown says that is not meaningful to them compared to an actual measurement of voltage at the output, which I have done, and it doesn't seem to make the grade. If my measurement is accurate, then 0.600 V falls short of the 1.5-2.0 Volts the Crown requires. Shiftline say the Olympic can easily drive the Crown, but in fact, it is not. Do you have accurate testing ability? What part of the world are you in?
Many emails with Shiftline. They have been nice, and have encouraged my testing. You state the 10db output, but Crown says that is not meaningful to them compared to an actual measurement of voltage at the output, which I have done, and it doesn't seem to make the grade. If my measurement is accurate, then 0.600 V falls short of the 1.5-2.0 Volts the Crown requires. Shiftline say the Olympic can easily drive the Crown, but in fact, it is not. Do you have accurate testing ability? What part of the world are you in?
good plan! Sounds like the Olympic pre is boogered. Can it be a dud/damaged?
I guess thats possible, but it sounds very good! Just low level compared to either my Kemper or my Hotone Ampero.....and of course my voltage measurements. I am hoping that Shiftline will offer to ship it to their Boston repair facility for testing.
If the Olympic can only output 0.6V, either it is faulty or not adjusted properly.
With the amp's sensitivity set to 0.775V, it should should be putting out significant power with 0.6V. I believe 0.775 to 0.6 is only about a 2dB difference
The 1502 is rated 525W at 4 ohms. It should hit this power level with 0.775V. With 0.6V I believe the amp should still make about 331W at 4 ohms. Not clipping, but still a good amount of power.
How are the attenuators on the amp set....turn them up all the way.
No I don't have accurate testing equipment. I am in the the US Midwest
Try to connect Crown to Olympic's jack output, not XLR. Use unbalanced Jack-XLR cable, where pin 2 is signal, and pins 1 &3 are grounded.
.......and I'm running the Crown in "bridged" mode, so I believe its about 500 w into 8 ohms. This is all so curious, and also such a simple set-up. Not much should go wrong. there's only two cables and a power supply.
which side to which connector?? unblanced out of the Olympic to balanced on the Crown?
- Feb 12, 2006
- 61,077
- 5
- 221,167
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
First, to avoid going down a rabbit hole, 1k output impedance is NOT a problem.
Second, if the published specs on the preamp are accurate, then either the pedal is not operating correctly OR there is a connection issue.
There are configuration options on many Crown power amps, and it's likely that one of these is the issue. Also, the level controls must be fully clockwise for rated sensitivity.
When bridging a Crown amp, you have only 2 options, either a special bridging SpeakOn cable with one end wired 1+/2+ and the other end wired 1+/1-. This cable will only work in one direction. The other way is binding post/MDP plugs.
Without knowing more about your speaker selection, I discourage bridging because it's more power than most speakers can safely handle without additional programming work.
be sure the crossover mode is not selected, select high input sensitivity, and that your output is really balanced.
Your bass should put out much more than 90mV, can you also try another bass?
Second, if the published specs on the preamp are accurate, then either the pedal is not operating correctly OR there is a connection issue.
There are configuration options on many Crown power amps, and it's likely that one of these is the issue. Also, the level controls must be fully clockwise for rated sensitivity.
When bridging a Crown amp, you have only 2 options, either a special bridging SpeakOn cable with one end wired 1+/2+ and the other end wired 1+/1-. This cable will only work in one direction. The other way is binding post/MDP plugs.
Without knowing more about your speaker selection, I discourage bridging because it's more power than most speakers can safely handle without additional programming work.
be sure the crossover mode is not selected, select high input sensitivity, and that your output is really balanced.
Your bass should put out much more than 90mV, can you also try another bass?
Yes. Be sure of wiring of XLR done right, as I described. Set amp's sensivity to 0.775V.
1/4 TS unbalanced on the Olympic side. XLR on the Crown side. Tip of the 1/4 goes to pin 2 of the XLR.
Per the Rane Connection Guide, this is the preferred configuration of the adapter:
Tip to pin 2
Ground to pin 3
Shield is connected only to the XLR side to pin 1.
Ref: [Invalid or Expired Link Removed]
Are there any virtual volume or gain controls in the Olympic's IR module?
Hi thanks for the feedback.
After just speaking with Crown tech support again, their belief is that the output voltage from the Olympic balanced out is just fairly weak, especially compared to the Kemper, who's output specs they researched.
According to Crown, since the balanced out is rated at +10 db, but the unbalanced out is rated at +20 db, they suggest I come out of the Olympic unbalanced (TS), and into the XLR on the Crown. BTW, to enable "bridged" mode on the Crown 1502 is just a simple selection in the menu. My Barefaced cabinet can handle that power for sure. I'm sure you're right about the bass output seeming low, but it's same as all of my passive basses. Since I don't have scope, all these measurements are rough at best. One downside of using unbalanced out of the Olympic is that it cabinet IR selections are only available in balanced. I think a design flaw. The other design which bothers me is that its aux input is only audible through it's headphone output. I think thats nuts, and very happy the TT-800 will not have that shortcoming. I like to practice with my iphone in an aux input fed to my cabinet rather than headphones because of a tinnitus issue. Perhaps the Olympic is best paired with another amp, an active bass ( or other instruments ), or in front of a standard bass amp-head or combo amp. Shiftline says though that it was not designed for that use. I think most guys use it that way.
Cheers.
NOT THAT I AM AWARE OF. CROWN AGREES WITH YOUR APPROACH. I JUST ORDERED A TS TO XLR CABLE. I HOPE ITS WIRED AS YOU SUGGEST.
HMMM. As it is now in bridged mode, isn't that being handled internally? I do have a Speakon cable connecting the Crown to the cab. Also, if this matters, only the left-side volume on the Crown has an effect, not the right. Wouldn't that indicate a successful bridge mode?You still need speakon 1+/2+ or bananas on said connections to get the bridge power
You're still only using one side. If the speakon connector you have is a 4 pole, then you can rewire one wire. Otherwise you'll need to grab a 4 pole end. The positive will be the 1+ and the negative will be the 2+. Then it goes in the channel one output. The back panel states this as well the manual if I recall, hehe
