Yellowguy

Gain make-up switch
« Reply #20 on: February 04, 2008, 05:05:30 AM »
I am very hesitant about using the cheapo switches for the gain make-up. This switch is effectively in the audio path.
Are there any alternatives?


Jim50hertz

Official 33609 builder's tread. See 1st page for updates.
« Reply #21 on: February 04, 2008, 07:24:42 AM »
http://www.technicalaudio.com/reading/neve_xfmrs/neve_edo7113.html

Looking at the data sheet here, if one wires an LO1166 primary in parallel and the secondary in series it should be usable in this circuit, or am I missing something?
"Nasty, talking to a slightly deaf journalist, had claimed only that the Rutles were bigger than Rod."

PimD

Official 33609 builder's tread. See 1st page for updates.
« Reply #22 on: February 04, 2008, 08:24:09 AM »
That's what i thought yeah.
and Takey said this
Quote
T3 is step-up transformer 70:600 / ~1:2.5 (+8dB) TF12009, L1173 or similar.

So looks like aLO1166 as 50:600 would work too. +10dB instead of +8 dB (but that could compensated with trimpot RV1)

So seems good too me.
Or does anyone know why it wouldn't work???

Yellowguy

Official 33609 builder's tread. See 1st page for updates.
« Reply #23 on: February 04, 2008, 11:17:20 AM »
Quote from: "PimD"

So looks like aLO1166 as 50:600 would work too. +10dB instead of +8 dB (but that could compensated with trimpot RV1)

So seems good too me.
Or does anyone know why it wouldn't work???


It might load the output stage to hard?
I can't think of any other potential problem.

PimD

Official 33609 builder's tread. See 1st page for updates.
« Reply #24 on: February 04, 2008, 11:37:27 AM »
Okay cool, well i can just try it, have one here so could try easy (only need too dive into measuring with transformers and all)

and then a question for igor.
Which Transformer has the biggest impact on the total sound.
because i may want too make it switchable between a cheap OEP, and an other one. (possible of not??)

Want too do this because i will first buy the OEP's, and later (when the money ship comes in) buy some better transformers.
And then it would be nice too have a choice for different flavours.

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #25 on: February 04, 2008, 06:31:36 PM »
Quote
I am very hesitant about using the cheapo switches for the gain make-up. This switch is effectively in the audio path.
Are there any alternatives?

Grayhill have same pinout switches, don't know exact cat. nr.
(edit: checked, this is C&K, not Greyhill)
There's goldplated Lorlins as well. I'll be in for 30-50 if someone
organise groupbuy for pcb version.
But, if you looking on schematic, RV1 trimpot affects audio
more than gain switch...
This way we can went in total audiofullery and...finnish the unit with
top MonsterCables 99,999999 puremonocristallic copper or something
like this. For me, it's OK, there was time when ESL63 at home
were connected with crazy good quality military silver-plated teflon cables ;)

Quote
Which Transformer has the biggest impact on the total sound.
because i may want too make it switchable between a cheap OEP, and an other one. (possible of not??)


Depends on level you feed into compressor.
If 0dbfs=+18, i.e. very hot, input OEP will saturate very hard.
Interstage OEP cuts a bit lows and adds more phaseshift on highs than Marinair/Beclair.

IMHO, worthy to try ungaped (2567 iirc) version of lo1166
at output connected pri's in series, there's still enough headroom,
 just re-calculate resistors values at gain switch and test. Will do this week.
I just asked a friend to wound me 1:2.5 trunnys on HI-B C-core
which I love for sound. This size bobbins are too big for my winding machine.
But hey, there's a lot of other substitutes, API output clone will fit,
Cinemag and Edcore have 1:2 outputs too.
Just...you know, as someone wrote there, mind is like parashute ;)
http://www.ij-audio.com
(new site hopefully will be up in July)

PimD

Official 33609 builder's tread. See 1st page for updates.
« Reply #26 on: February 05, 2008, 09:34:08 AM »
I guess i will try the CA-18-VTB9057 (ungapped 2567) then. Wired Pri - Series, Sec - Series (200:600 +4dB)

And i will use the OEP on In and Interstage, and maybe make the input so i can switch it (in a later stage)

Yellowguy

Official 33609 builder's tread. See 1st page for updates.
« Reply #27 on: February 06, 2008, 05:54:02 AM »
Quote from: "Igor"

But, if you looking on schematic, RV1 trimpot affects audio
more than gain switch...


I can see what you are getting at :wink:  
However, the trimpot is set once and then left there. Maybe recalibrated once every 2 years, if ever.
The gain switch (that is in the audio path just as much as RV1, it's in the negative feedback loop of the output amp) will be used on a regular basis. As soon as it starts to get worn or oxidated, we will be getting loud cracks and pops or dropouts when adjusting it. This could happen pretty fast :cry:

Now let's not get into the exotic cable debate, nothing good ever comes from it :green:

/Marco

Yellowguy

Official 33609 builder's tread. See 1st page for updates.
« Reply #28 on: February 06, 2008, 06:28:38 AM »
For Grayhill switches, is this the one? Farnell code 1190385

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #29 on: February 06, 2008, 08:52:50 PM »
Quote
For Grayhill switches, is this the one? Farnell code 1190385

No, this one won't fit.
Sorry, it is C&K, my bad sectors ;)
http://www.ck-components.com/media/pdf/catalogs/Rotary_Switches/A_Rotary_August_2007.pdf

Manufacturer: C & K

Order Code: 1701630

Manufacturer Part No: A11215RNCQ


Quote
Igor wrote:
But, if you looking on schematic, RV1 trimpot affects audio
more than gain switch...
I can see what you are getting at  
However, the trimpot is set once and then left there.


Hey, but this affects sound more than switch!

Potentiometers DO distort, audio is chaotic (pulse randomal) signal,
it is never sinwave, etc.

I am OK with this trimpot there, even in case my ESL-63's were connected with very freaky cables ;)

IMHO just use Lorlin, type in BOM is shorting (make before break),
made in UK,  very good contact quality till you put this in smoking room
(as all silverplated contact switches).
Don't use Alfa chinese replacement. These no good.
http://www.ij-audio.com
(new site hopefully will be up in July)


Yellowguy

Official 33609 builder's tread. See 1st page for updates.
« Reply #30 on: February 07, 2008, 06:07:29 AM »
Quote from: "Igor"

IMHO just use Lorlin, type in BOM is shorting (make before break),
made in UK,  very good contact quality till you put this in smoking room
(as all silverplated contact switches).


Ok Igor, I will just have to trust you on this!

Another thing that I'm not clear on: Is there a PS board in the kit, or do we have to make up our own here?

/Marco

PimD

Official 33609 builder's tread. See 1st page for updates.
« Reply #31 on: February 07, 2008, 07:20:27 AM »
Quote from: "Yellowguy"


Another thing that I'm not clear on: Is there a PS board in the kit, or do we have to make up our own here?

/Marco


And if so could you include the parts in the BOM??
And also the parts for the BA340 (or at least the farnell part numbers for tr1 - tr 7)
Want too order the parts asap.

And again, thanks for making this possible  :green:  :thumb:

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #32 on: February 08, 2008, 12:36:33 PM »
Order Code: 9207104
Manufacturer Part No: BC461  
 
Order Code: 356992
Manufacturer Part No: BC441.
 
 Order Code: 1017657
Manufacturer Part No: BC184C
 
Order Code: 1017665
Manufacturer Part No: BC214
http://www.ij-audio.com
(new site hopefully will be up in July)

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #33 on: February 08, 2008, 12:43:03 PM »
BA 340 BOM

RESISTORS
1 5k trimpot bourns 25t    RV1          
2   1R5    R-EU_0204/5     R13, R14    
1   2K2    R-EU_0204/5     R7          
1   2K7    R-EU_0204/7     R5          
1   10K    R-EU_0204/5     R11          
1   15K    R-EU_0204/5     R16          
1   18K    R-EU_0204/5     R2          
1   36K    R-EU_0204/5     R1          
1   47K    R-EU_0204/5     R6          
1   47K    R-EU_0204/7     R3          
1   150    R-EU_0204/5     R10          
3   560    R-EU_0204/5     R8, R9, R12  
SEMICONDUCTORS
2   BC184. BC184.          TR2, TR3    
1   BC214  BC214           TR1          
3   BC441  BC441           TR5, TR6, TR7
2   BC461  BC461           TR4, TR8    
1   GE     AA144           D3          
2   SI     1N4148          D1, D2
CERAMIC CAP
1   10n    C-EU075-032X103 C5  
ELECTROLITHIC CAPS
1   10uF   CPOL-EUE2.5-6   C2      
1   22uF   CPOL-EUE2.5-6   C1
POLY OR COG
1   220p   C-EU050-024X044 C3
http://www.ij-audio.com
(new site hopefully will be up in July)

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #34 on: February 08, 2008, 12:44:29 PM »
Quote
Another thing that I'm not clear on: Is there a PS board in the kit, or do we have to make up our own here?

Included. Will post schem and layout within some days.
http://www.ij-audio.com
(new site hopefully will be up in July)

Yellowguy

Official 33609 builder's tread. See 1st page for updates.
« Reply #35 on: February 08, 2008, 04:02:05 PM »
Quote from: "Igor"

Included. Will post schem and layout within some days.


Beautiful! :thumb:
I can't wait to get started, when can we expect the pcb's?

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #36 on: February 08, 2008, 08:25:25 PM »
I expect to get pcb's from manufacturer on 20-22 feb.
http://www.ij-audio.com
(new site hopefully will be up in July)

waldorfcave

Official 33609 builder's tread. See 1st page for updates.
« Reply #37 on: February 11, 2008, 03:25:30 AM »
What kind of meter do we need :?:

PimD

Official 33609 builder's tread. See 1st page for updates.
« Reply #38 on: February 11, 2008, 03:30:36 AM »
Take a look at the second page of the BOM, which can be found on the first page.
But it's a Sifam AL19

Igor

Official 33609 builder's tread. See 1st page for updates.
« Reply #39 on: February 15, 2008, 04:11:09 PM »
More pics uploaded.
See 1st page.
http://www.ij-audio.com
(new site hopefully will be up in July)


 

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