Tag Archive: EQ

Studiomaster 16-4-8 restore

paul post on September 24th, 2008
Posted in Technology Tags: , , , , , , , , , , , , , , , , , , ,

Hi, so I’ve just picked up an old Studiomaster 16-4-8 in great condition. Its just a bit noisy, Id like to recap it and mod it.
I have some info such as:


I went through a few of these around 20 years ago. Installing local .1 uf bypass caps on the power rails does help. All feedback loops need to have a small cap across, most stages had them. Use Wima FKP-2 or MKP-2 polyprop caps in the EQ, especially the hi mid and hi shelf. Opamps can be the older OPA 2134 BurrBrown stuff, the LT1358, the OP-275, the AD 8599 (with a brown Dog adaptor) or the National LME49720/LME49860, balanced outputs can use the National LM6172 for great output drive. Also check out the new AD8510 series, a BurrBrown fet input sub for the OPA134 series. Mic pre transistors can be 2SA1316 or 2SA1083’s to lower front end noise and add some HF air. A nice big Power One HDD-15-5A will be a good power supply if you add the small 1/2 amp 48 volt supply for phantom. Then you can play with opamps all day long. The summing amps in the master should be the National LME part due to it’s large open loop gain, = a clearer mix buss.
Jim Williams

and

I started by the power supply caps; major improvement in noise and hum. I found out that most original caps were rated low, like 16 volts for a 15 volt power supply, so I used 25 volts throughout (except where the design called for higher voltage).

and

Replace with the same type of capacitor to the one you remove. So, if you remove a 10uF or 22uF tantalum capacitor, you do NOT replace it with an aluminium electrolytic!
2. Neve designers were restricted back then on the size of capacitors and, in the case of the power decoupling to the 183/283 (fitted to the frame of the module), fitted the largest value that could fit in there… usually 640uF. I personally recommend fitting the largest capacitor that you can now fit in there… like a 4,700uF which may be the same size now as the original.
There is nothing to be gained (and, indeed factors may go against you in extreme cases) by using a much higher voltage electrolytic capacitor. You should fit one as close to the operating voltage as you can. 35v is probably a good, top limit, value.
3. As for capacitors on circuit boards… remembering the warning about substituting tantalums for other types… there’s no harm in fitting bigger value capacitors if they will fit. If it’s decoupling the power rail, it will decouple slightly better. If it’s decoupling between two amp stages or an emitter bypass, it will improve the bass response marginally.
Geoff Tanner

Here are the links to pics:

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Filters & OS

paul post on January 4th, 2008
Posted in Technology Tags: , , , , , , ,

Hey man, hope all is well
had major problems today
my multi os keeps crashing/restarting
probably to do with cracked acronis
it only sees the 1 os
probably gonna wipe all and start again
wont use my acronis, just do multi boot then tweak boot.ini file to make names easier to read instead of 3 x microsoft home xp

do you think its possible for me to make an eq with HPF, LPF and 3 x parametrics in one box(HPF & LPF have to be variable)?

let me know your thoughts

thanks Paul

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Zombie Dance – Mary Whitehouse

INSERT_MAP I’ve used some extra software that I’ve “re-found” (!!!) on my PC to adjust the sound a bit (well a lot actually) of these two consecutive tracks from a live gig recorded at “The Golden Eagle” pub in Blyth, Northumberland in 1980-ish. The sound is pretty crap on the cassette and the tape is old (I’ve already had one break), so it’s taken a while and I just can’t get it right without taking too much away. The newer clean-up can be found on the Crawling Chaos site here.

The software is the HarBal Equalisation System for windows operating systems version 2.3 revision 1

Just trips off the tongue really… You can get it here and there’s a SoundOnSound article here.

I found it quite neat to use and it does smooth out the sound when you work at the settings. It doesn’t seem to like high bit rates i.e. anything better than CD quality. Next time I’ll pre-EQ and then clean up and maybe post clean-up EQ again to see what happens. A neat thing is the harmonic picker-outer (technical phrase – harmonic cursor), where you can select a peak and it points out the 2nd, 3rd, 4th etc harmonics to that frequency and you can see if any coincide with other higher frequency peaks. The third harmonic is the killer because it’s discordant. I found one major peak that had a peak on it’s third harmonic. Reducing this removed loads of harshness. This is why I think it’d be a good experiment to try this tool BEFORE noise reduction etc – I think I can chop off the hiss without data and kill a few duff harmonics to make the noise removal process more effective.

Watch this space!

I’ll give my ears a bit of a rest and then go back to them to choose the best one. If anyone has any preferences about what to leave up then speak up now.

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70’s Mixer

paul post on July 4th, 2007
Posted in Buddhism Tags: , , , , , , , , , , , , , , , , ,

Hi, hope all is well. What you been up to? Any music stuff? I am hopefully picking up an old 70s mixer. The inputs and outputs are 5 pin din connections. I want to add some xlrs and direct outs. What is A. the best way to do this? 2. How is the best way to learn about electronics? I purchased Designing Audio circuits, but I still really cant get my head around it. I would like to make some dealy boxes, the progress to transformer based pre-amps, EQ and Compressors. Any help, tips, information would be great. I would love to understand electronics for this. Favourite outboard would be Neve, API, UA 1776(vintage stuff) Thanks
http://myspace.com/paulrichards7

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