S800 Support Thread

[craigmorris74]

Thanks for the tip, Andy.  I'll check this first.
Craig

 

[Ngr]

Finished my unit.
It works ok, but I have a few problems:
frequency range of the parametric filters seems to be wrong, the frequencies marked on Purusha's case do not correspond to what it's actually happening: boosting 1.5k i.e. results in boosting a lower frequency and generally speaking the pot span does not seem to be correct with the frequencies marked on the case.
And more, when in bypass, the unit output is higher (0.6-0.t dB) than when eqs are on with all gain pot at zero.
Any chance to fix those problems?

 

[Benny]

Hey there,

I think you can set your eq to unity gain with an onboard trimmer.

Ben

 

[Ngr]

trimmer affects unit output in both bypass and on position...

 

[craigmorris74]

I resoldered a few componenets, and now the high-mid is working, but now both channels have a synth like tone that changes when the EQ's are bypassed.  Any thoughts as to what could cause this (was very quiet before).

Thanks,
Craig

 

[Hammond]

Quick question, where do i connect the bypass led?

 

[RedNoise]

in the two holes between Sw1 & the next pot...IIRC.

 

[evolver]

Hey everyone

i am very much a n00b and wanted to run this by some people with more experience. To date my experience has been putting together some SCA preamps -- which work. I ordered the following:

AML electronics and knobs kit x2
Purusha's case + PCB&PSU boards

I put all of the electronics from one of the AML kits on a board this weekend. I  am now trying to sort out what further parts i need to order to finish this bad boy.

It seems i need the following for the S800 itself:

(i am getting two of the PCB parts, since i am building a stereo unit)

S1, S2, S3  are 6 x SPDT
I read on here that the following would work for the SPDT:  Mouser  108-1M31T1B1M1QE-EVX (http://www.mouser.com/Search/ProductDetail.aspx?R=108-1M31T1B1M1QE-EVXvirtualkey12040000virtualkey108-1M31T1B1M1QE-EVX)
S4  is  2 x 4PDT
I did not see a potential part listed on this thread. Can anyone offer any recommendations ? 
Input  XLR-F x 2 
Output  XLR-M  x 2
1 x LED ( i think i only need 1 for a stereo unit, correct ?)
Is there anything special i should look for in getting the in/out and LED parts ? 
PL1, PL2  are  2 x Molex 3
PL3  is 1 x Molex 3 Big
the molex connectors are the little white socket-thingies that let you easily plug and unplug
a powersupply correct ? are there specific part numbers recommended that will fit more easily onto
the PCB ? 

For the PSU (non-48v) i need the following:
Capacitors
4 x 100nF mouser part: 647-USR1H0R1MDD ( http://www.mouser.com/Search/ProductDetail.aspx?R=USR1H0R1MDDvirtualkey64700000virtualkey647-USR1H0R1MDD )
4 x 1000uF mouser part: 647-UHM1A102MPD6 ( http://www.mouser.com/Search/ProductDetail.aspx?R=UHM1A102MPD6virtualkey64700000virtualkey647-UHM1A102MPD6 )
2 x 10uF / 35v mouser part: 647-UKL1V100KDD1TA ( http://www.mouser.com/Search/ProductDetail.aspx?R=UKL1V100KDD1TAvirtualkey64700000virtualkey647-UKL1V100KDD1TA )
Resistors
4 x 220 mouser part: 271-220-RC  ( http://www.mouser.com/Search/ProductDetail.aspx?R=271-220-RCvirtualkey21980000virtualkey271-220-RC )
2 x 2k2 mouser part: 71-CCF07-G-2.2K  (  http://www.mouser.com/Search/ProductDetail.aspx?R=CCF072K20GKR36virtualkey61300000virtualkey71-CCF07-G-2.2K  )

Misc
2 x 1N4007 mouser part: 512-1N4007  ( http://www.mouser.com/Search/ProductDetail.aspx?R=1N4007virtualkey51210000virtualkey512-1N4007 )
1 x LM317 mouser part:  512-LM317T ( http://www.mouser.com/Search/ProductDetail.aspx?R=LM317Tvirtualkey51210000virtualkey512-LM317T )
1 x LM337 mouser part: 512-LM337T ( http://www.mouser.com/Search/ProductDetail.aspx?R=LM337Tvirtualkey51210000virtualkey512-LM337T )

The following two i filled in from scanning this thread for recommendations. Are these
still considered good choices ?

1 x Bridge Rectifier mouser part: 583-BR64  (  http://www.mouser.com/Search/ProductDetail.aspx?R=BR64virtualkey58300000virtualkey583-BR64 )
1 x Transformer mouser part: 553-FP30-400  ( http://www.mouser.com/Search/ProductDetail.aspx?R=FP30-400virtualkey55310000virtualkey553-FP30-400 )



One thing i did not see when scanning the thread was what sort of cable i needed to connect the PSU
to the PCBs via the molex connectors. is this a "one sized" standard type of cable or is there something
more specific that i will need?


Sorry for all the questions -- i am trying not to make any stupid mistakes in doing this build. if you can chime in on a point or two and not the whole thing i would still be very appreciative.

 

[Brolik]

One thing i did not see when scanning the thread was what sort of cable i needed to connect the PSU
to the PCBs via the molex connectors. is this a "one sized" standard type of cable or is there something
more specific that i will need?

couple of 22 gauge wires with the right molex connectors will do the trick. I think its .156 inch pitch. Mouser part # 538-09-50-3031 should work. You'll need a couple terminals as well, 538-08-50-0108 should do just fine. I would go ahead and buy a bunch of extra terminals as you're likely to screw up the first couple tries. If you're looking to daisy chain several with one cable (if you're making an 8 channel for instance) it would behoove you to get terminals that accept a larger gauge wire (538-08-50-0106)

 

[evolver]

OK -- so I have one board stuffed, and the PSU board stuffed -- i have a new n00bish question.

Given the attached image, which numbered pins on the Transformer do I attach to the 2 ACs holes and the Ground hole on the PSU board?

( This is the first time i have had to wire a power supply -- to date i have only put together SCA pres and put them in a case+PSU i bought from another guy. )



thanks for your help!

(ps -  i had an error trying to post this the first time, hopefully a duplicate doesnt pop onto the thread)

 

[peterc]

Give us a clue, what are the transformer connections?

Also check this page:

http://1176neve.tripod.com/id26.html

 

[evolver]

Give us a clue, what are the transformer connections?

Also check this page:

http://1176neve.tripod.com/id26.html

can you give me a clue how to figure that out ? i tried reading up on input transformers but most of what i found was just discussions of what they do, or different types. there are 8 pins on it, on one side numbered    3421  and on the other side  7865    I looked in the document sheet but didnt see anything as obvious as "pin 1 is hot, pin 2 is cold" (which is what i basically need).

 

[Harpo]

Give us a clue, what are the transformer connections?

Also check this page:

http://1176neve.tripod.com/id26.html

can you give me a clue how to figure that out ? i tried reading up on input transformers but most of what i found was just discussions of what they do, or different types. there are 8 pins on it, on one side numbered     3421   and on the other side   7865    I looked in the document sheet but didnt see anything as obvious as "pin 1 is hot, pin 2 is cold" (which is what i basically need).

Get the transformers datasheet from the link you already posted, if it really is mouser part: 553-FP30-400, else get it for YOUR transformer.
Depending on your location (please update your profile, this is an intercontinental forum and mains voltages differ),
- for 115VAC mains connect the transformer primaries in parallel by linking pin 1 with 3 and pin 2 with 4. These 2 junctions connect to your IEC inlet with fuse and mains switch in between.
- for 230VAC mains connect the transformer primaries in series by linking pin 2 with 3. Transformer pins 1 and 4 connect to your IEC inlet with fuse and mains switch in between.

The transformer secondaries pin 5 and 8 connect to the two holes labled 'AC' on your supply pcb. Link transformer secondaries pin 6 and 7 and take this junction to the pcb hole labled 'GND'.
good luck

 

[mitsos]

haha! This time you beat me harpo!!

A small question for you...  on the datasheet, pin 5&7 are hot and 6&8 are cold. The way you are suggesting, the secondaries are in series and you are connecting the "center tap" to ground. What is the difference between this and connecting the two hot pins to each AC and the two cold pins to AC ground?

 

[Harpo]

on the datasheet, pin 5&7 are hot and 6&8 are cold. The way you are suggesting, the secondaries are in series and you are connecting the "center tap" to ground. What is the difference between this and connecting the two hot pins to each AC and the two cold pins to AC ground?

Difference is a working psu. For this psu design you want a center tapped transformer. Imagine this a single winding secondary with in-phase and out-of-phase potential at its end terminals and a phase-neutral tap in the middle. For same behaviour you connect a dual secondary to substitute this imaginary center tapped transformer as described above.
The transformer following rectifier is in between both end terminals (no connection to the center tap), sorting the positive and negative halfcycles to the 2-anode-side and 2-kathode-side diode junctions for +/- ends. The rectifying diodes have to see a differing voltage potential to do so.

 

[mitsos]

I guess it helps to check a schematic now and again before posting, eh?  :-[

 

[evolver]

Depending on your location (please update your profile, this is an intercontinental forum and mains voltages differ),

updated -- sorry for the breach of etiquette. I am in NJ / USA.


thanks

 

[evilcat]

Hi everyone !

I've nearly finished my 1st unit. Before plugging the TL071s, is there any test measerements to do ?
Thanks.

 

[RedNoise]

check voltage accordingly to the DIP8 config!

 

[Tungstengruvsten]

just got mine up and working and the LMF is off in it's frequencies(but starts at the right bottom frequency) ...and displays a weird waveform compared to the HMF - here's some AP curves....

HMF


LMF




It seems that the available boost and cut goes down as the frequency of the LMF goes up...anyone seen this before?  Is this normal for these? part of their sound?  because they sound frickin' awesome on guitars!