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Hi Leif,
I have downloaded your BBP ASIO demo with a dedicated Quad core computer and using a EMU 1212 card. What are the I/O settings for mono AM? Using a single channel I can get line level out from the BBP but it doesn’t change the audio with different setting like changing the LP filter. The BBP Demo meters are working but the one AM drop down (asymmetry) will not allow any setting change and the bypass mode also does not change the audio quality out. I am ready to order the BBP ASIO but I am only interested in the AM side of your great processor but it seems the main threads on the boards are primarily geared towards FM so let me know if need to order the BBP ASIO to find that AM menu.
Thanks and I can’t wait to put your BBP on the air.
RobertAll settings apply to the latest (.93) version..
To begin with, if you are using AM, you will need to de-select Stereo in the settings section. Secondly, you will not need pre-emphasis selected either (put down to 15us).
In the calibration screen, I would first of all apply the bandwidth to 5Khz, and the HPF to 30Hz, which it will be on anyway.
In the I/O config screen, Disable the RDS in if not already done and disable the main output (this will bring up the AM sub-menu when you go back into the calibration menu) and then set the L/R output as your main output card. This will then give you an AM compliant mono output. Go back to the calibration menu and adjust the AM asymmetry slider to the desired level (25% for 125% positive peaks). The difference will not be immediately obvious visually but if you (temporarily) put the final drive right to the top and then adjust the asymmetry slider up, you will see the bottom of the trace lifting upwards, this is your visual confirmation that BBP is now producing positive peaks.The preset/audio settings you use are entirely down to your own taste and requirements, try a few and play with the sliders until you get a sound you like.
I’m not sure (maybe someone can help here) if the Tilt calibration is required for AM, I’m kinda guessing not but I could well be wrong here, CMIIW people..Finally, unless you are using the E-Mu 1212 for a specific quality reason, this is major overkill for AM, the 192Khz operation is only required for FM stereo operation. ANY soundcard will be fine for AM, even an onboard card will give a more than good enough SNR for AM.
Hope this helps,
Yorkie.
AM does use pre-emphasis.
and the NTSC spec for AM allows for 10kHz of audio bandwidth. no reason to limit it to 5kHz unless you WANT to sound worse.
And no soundcard is ever "overkill" for anything, unless you’re talking about a 13 year old kid playing games or something. This is broadcast baby.
[quote author=”JesseG”]AM does use pre-emphasis.
and the NTSC spec for AM allows for 10kHz of audio bandwidth. no reason to limit it to 5kHz unless you WANT to sound worse.
And no soundcard is ever "overkill" for anything, unless you’re talking about a 13 year old kid playing games or something. This is broadcast baby.[/quote]
True comment Jesse about the soundcard, I’m just such a skinflint at times, always looking for that economy/quality sweetspot. I’ll take my hat off to the first person who uses a Trace Alpha for AM..
My setup was for the European AM specification where I live in the UK, the audio bandwidth is 40hz -5khz.
So, Robert, set the HPF and LPF filters accordingly for your territory/license. As for the pre-emphasis, again, none used here in Eurozone AFAIK but if appropriate for your territory then of course set to required time constant.
[quote author=”yorkie98″]My setup was for the European AM specification where I live in the UK, the audio bandwidth is 40hz -5khz.[/quote]
Maybe your receiver restricts it to that range, but MW stations in the British Isles typically transmit with at least 6 kHz of audio bandwidth, at least for music formats.As Orban boasts in their Optimod 9300 brochure (but I’m sure the same is true about Breakaway!): "The 9300’s output power spectrum is so tightly controlled that stations in Europe are able to operate with filtering as high as 6.0 to 6.5 kHz while still complying with ITU-R/EBU occupied-bandwidth regulation! This greatly improves the received sound as compared to conventional 4.5 kHz filtering."
In the Western Hemisphere, 10 kHz audio bandwidth is commonly used on AM. And I have recordings of AM Stereo stations in Japan that are transmitting 12.5 kHz audio (the maximum bandwidth allowed by the Optimod 9100) with quality and fidelity that gives FM a good run for its money — even over skywave!
[quote author=”yorkie98″]I’m not sure (maybe someone can help here) if the Tilt calibration is required for AM, I’m kinda guessing not but I could well be wrong here, CMIIW people..
Yorkie.[/quote]Aside from what adjustments you might need to fix tilt issues in your chosen soundcard, It is possible that further adjustments will be required to get maximum modulation from your transmitter. Newer models are much better in this area. However, the adjustments will allow you to easily tune up even ’60s vintage tube tranmitters.
Once you’ve installed Breakaway into your audio chain, you’ll have to scope the transmitter to determine what adjustments, if any, will be required.
Hi to all,
Thanks Yorkie for your setup info but my demo (90.78) will not allow me to get to the AM sub menu. With RDS disabled this is my I/O configuration: EMU 1212 ASIO Input set up with L&R input with the RDS/Pilot and all FM related inputs are off. The L&R studio out are going to the only option given which is the ASIO 7/8 strip located on the EMU and all FM related outputs are off.
The BBP demo will accept the input program content from the EMU, meters show the processing taken place including the output but the audio out is not being processed but my program input is going straight to the output. The internal tone generator shows up on the scope but not at the audio output.
Thanks for the suggestions on the signal setting but this is where I am quite at home. I have the pleasure of setting up many stand alone processors (Omnia, CRL, Inovonics) which I primarly use these on the vintage tube broadcast transmitters. I need the LF Phase and Hf delay for tilt and overshoot corection with heavy mod iron so I hope Leif has it on the purchased version of BBP. The main feature for me is the low and HPF because on the ham bands we need to control bandwidth and running 5KHz wide audio (10KHz RF) the HF-Emphasis is a must.
The processors I now have all use the NRSC 9.5KHZ filters and breadboarding 5th and 9th order elliptical filters with group delay and overshoot correction is a waste of time compared to downloading the BBP.
Bottom line! Is my problem in my BBP ASIO demo with limited AM setup functions, sound card setup or lack of software knowledge. Note: I also tried my 192K/24B B-enspirer SC and had the same results stated above.
Thanks for your input folks!
RobertYou can demo the newest version. .93, I think… Just uninstall yours and install this new one… Any version can be demoed. The AM menu may have been added since .78.
Good luck.
Thanks Timm… Where can I find the lastest demo download? I only see the 90.78 listed on the ClaessonE site. Maybe it is time to just purchase it and hope the new version will work!
RobertAt this link: viewtopic.php?f=5&t=781
Enjoy!
Hi Fellow BBP users,
I downloaded the .93 version on my stand alone (XP) quad core compuer with a EMU 1212m card to handle the ASIO chores. I am now getting a change in the audio response from the screen panel controls on the BBP so all is well up to that point. My apps for the BBP is AM so I need to know if any one using the Demo can get to the AM calibration menu to show on the screen or work. I have the RDS disabled and everything else related to FM off but the asymmetry does not change from 0%, the invert I/O will allow you to click on but no changes are seen on the scope with the phase scrambler off. The high and low pass filters perform the same way by allowing you to select a value but there is no change in the bandwidth or am I missing something? It is like the ASIO version was designed for FM only. Can someone please tell me if the ASIO purchased version will have the Phase and tilt correction and all the menus for AM functional because even with me using the limited amount of controls I can see this could be a great AM processor. I also set up the Demo BBP non ASIO version and all the AM menu’s worked just fine but the excessive latency will not work for me with live broadcasts. Thanks for the input!
RobertHi RJ,
For sure the HPF was on and tried in all settings. On my demo version (.93) there is not a box in the menu for tilt or LF phase correction and it was the asymmetry (AM) box which isn’t grayed out but will not change from the value of 0%.
I tried to contact Keith twice to answer these simple questions about the demo download vs the purshased version but heard nothing as of yet because before I buy his fine BBP ASIO I need to know that AM is still incorporated in the software. Thanks!
RobertIt *should* be incorporated. If it’s not working, then it’s totally a bug. It is possible that it’s a bug because I found one in the speaker controller in Live too. The bug got introduced when Breakaway’s core upgraded to a 64bit audio path.
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