Very professional, I love it always in rack mount.
The BBC AM1/11 equalizer and or Blonder Tongue Audio Baton schematic IIRC appeared in a quite old engineering publication. I have been trying to find this on my server, or find the schematic I possibly re-drew of it from that old mag and compare.
No luck so far, but I think it is the same, the tip-off is the last (lower) stage, dual purpose highest and lowest bands, 10240 and 40 Hz.
Great topic, so many good information and designs to do more thinking about!
The BBC AM1/11 equalizer and or Blonder Tongue Audio Baton schematic IIRC appeared in a quite old engineering publication. I have been trying to find this on my server, or find the schematic I possibly re-drew of it from that old mag and compare.
No luck so far, but I think it is the same, the tip-off is the last (lower) stage, dual purpose highest and lowest bands, 10240 and 40 Hz.
Great topic, so many good information and designs to do more thinking about!
Thank you for your comment....all the best
Thank you for the info I will for sure consider this website....all the best
Google found a poor scan, first hit.
Jack's Photos: The Blonder-Tongue Audio Baton
Links, down the bottom.
The BBC unit added 220V power and proper radio-network output stage.
I think this schematic looks quite similar:
http://www.jogis-roehrenbude.de/Verstaerker/Equalizer-large.jpg
http://www.jogis-roehrenbude.de/Verstaerker/Equalizer-large.jpg
The Blonder-Tongue Audio Baton replica on the way, I just finished one channel and test it.
I stick to the original schematic but I add a 5 led bar graph, led VU meter and an unusual power supply that works very well.
The second channel will be upside down for fit inside a 3U cabinet and when finish will looks as the picture of the front panel. Both channel will be completely independent.
Sound is excellent just some minor noise issue but I will work out on it, this is just the first test.
All the best to everybody.
I stick to the original schematic but I add a 5 led bar graph, led VU meter and an unusual power supply that works very well.
The second channel will be upside down for fit inside a 3U cabinet and when finish will looks as the picture of the front panel. Both channel will be completely independent.
Sound is excellent just some minor noise issue but I will work out on it, this is just the first test.
All the best to everybody.
Attachments
That little boost module might be your source of noise. I have found them to be terrible, quite frankly.
I would recommend trying one of these instead if you do determine it's coming from the boost module.
DC-AC Converter 12V to 110V 200V 220V 280V 150W Inverter Boost Board Transformer | eBay
Awesome project man.
Koda
I would recommend trying one of these instead if you do determine it's coming from the boost module.
DC-AC Converter 12V to 110V 200V 220V 280V 150W Inverter Boost Board Transformer | eBay
Awesome project man.
Koda
Hi Koda thank you very much for the tips, on the first test was very terrible then I add a resistor and 100uf cap and the bad noise goes away, the remaining noise is very small and I think is because all the potentiometer are not grounded yet, but I want for sure try the inverter boost you suggested, I know you have a big experience on it....thanks again
You're welcome. Since you're in the Philippines, you can probably find another seller that offers them for like 1/2 the price. Look around on eBay and Ali.
One nice thing about the one I linked is it's push pull instead of SE, and it's isolated. I use them for negative supplies for bias, too
One nice thing about the one I linked is it's push pull instead of SE, and it's isolated. I use them for negative supplies for bias, too
I already find it https://shopee.ph/SUNYIMA-DC-AC-Con...oard-Transformer-Power-i.307967930.5163547118 thanks
I received yesterday and test it and all noise gone, this is really a good product, thanks Koda....all the best
The Blonder-Tongue Audio Baton replica now finally finish, initial noise problem was due to the boost module of poor quality, thank to "kodabmx" with different boost module all noise are gone.
I am very happy with the result and most of all sound beautifully, frequency interaction work very well living space for some interesting effect.
The two channel are completely independent so very flexible adjustments on frequency response, full waive VU meter, THD 0.15%.
The most difficult task has been the space in the 3U cabinet, really a question of millimeters for host the two channel.
Really happy to bring back from 1959 some electronic master piece and more happy on 2021 to enjoy the music.
I am very happy with the result and most of all sound beautifully, frequency interaction work very well living space for some interesting effect.
The two channel are completely independent so very flexible adjustments on frequency response, full waive VU meter, THD 0.15%.
The most difficult task has been the space in the 3U cabinet, really a question of millimeters for host the two channel.
Really happy to bring back from 1959 some electronic master piece and more happy on 2021 to enjoy the music.
