Author Topic: MM Phono Stage  (Read 2840 times)

Offline ajscheid

Re: MM Phono Stage
« Reply #150 on: September 11, 2019, 08:08:52 PM »
FYI - Communica has these bits in stock for transformer , powerplug and socket , it says DC plug/socket but will be fine for 16VAC . Also an easier hole make in aluminium backplate if you dont have a milling machine at home .  ;D

That power supply is waaaaaaaay to big for my taste!! As per muffsy you need a minimum of 0.1A to be delivered; So that would be at 18V  1.8VA!!!!!
I think I will order one in China together with the 0905 enclosure and be set. Aliexpress has these:
https://www.aliexpress.com/item/33015635712.html?spm=a2g0o.cart.0.0.31b83c00JFHk8I&mp=1; 18V AC out with 9VA. That should be sufficient.

Online fredeb

Re: MM Phono Stage
« Reply #151 on: September 11, 2019, 09:28:46 PM »
I like over-provisioning  ;D , and can't afford to spend money on enclosures ATM , so I'm just going to build it into a lunchbox , or Chinashop wooden treasure box .  ;D
...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts

Offline Aqualung

Re: MM Phono Stage
« Reply #152 on: September 12, 2019, 07:08:58 AM »
The M-PP3 components have arrived! This is for 5 Cape Town builds. M-PSU components are on their way...


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I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline vinyljan

Re: MM Phono Stage
« Reply #153 on: September 12, 2019, 07:25:07 AM »
I've tested some phono builds with X2 9V batteries in series, can be used long term as well, not sure how many hours you'll get from a pair?
In a maximum bank turn in a normal category airplane, like a typical Cessna, everything is fine until you turn across your own wake

Offline ajscheid

Re: MM Phono Stage
« Reply #154 on: September 12, 2019, 08:27:09 AM »
So finally I ordered all my stuff. I went with the 0905 housing and the above power supply I posted earlier; I like neat... :pleasant:

So total cost including all shipping cost then come to:

Mantech order: R592,19 (includes all back panel parts except the back panel itself)
Aliexpress order: $25 equals R340,00
PCB's from Dirk: 440,00 inlcuding shipping.

That's a total of around R1380,00 and approximately half of what an ordered kit at muffsy would have been (PSU factored in).

Looking soooo forward to built this little gem.  :Whoohoo:

Online fredeb

Re: MM Phono Stage
« Reply #155 on: September 12, 2019, 10:53:34 AM »
The M-PP3 components have arrived! This is for 5 Cape Town builds. M-PSU components are on their way...

Woo-hoo ! Now to wait for manufacturers to finish the PCB's , round about the end of the month I guess .


« Last Edit: September 12, 2019, 10:56:39 AM by fredeb »
...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts

Offline Aqualung

Re: MM Phono Stage
« Reply #156 on: September 13, 2019, 04:53:52 PM »
I stopped working early today, and came home at 3pm to start scratching through my "old parts" box
for an 18VAC transformer for my Muffsy PSU build.

I found two: one is the size of a half-brick, and weighs a ton, and one is about the size of a matchbox (just more square).
The small one has only one output, and it measures 18.4VAC.
The large one has selectable mains input, 220VAC and 250VAC. I measured my mains today, and it is 240.3 VAC.
I set the input to 250 VAC, and measure 17.98 VAC on one set of the secondary windings (there are 3 others).

My question: which one should I use, and why?  :thinking:  :teach:

(I don't mind a big transformer, in a different box, standing on the floor and feeding the Muffsy PSU, if there is any benefit to that.)
I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Online fredeb

Re: MM Phono Stage
« Reply #157 on: September 13, 2019, 05:19:25 PM »
I'd go for the bigger one - power to spare , on tap can never be disregarded . 

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...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts

Offline Family_Dog

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Re: MM Phono Stage
« Reply #158 on: September 13, 2019, 05:23:35 PM »
This one is fine, and allows a margin of safety.

>> I set the input to 250 VAC, and measure 17.98 VAC on one set of the secondary windings


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Online fredeb

Re: MM Phono Stage
« Reply #159 on: September 13, 2019, 05:25:05 PM »
BTW - there's a dingey little shop close to me that sells secondhand lp's . I found this faux leather wooden box there . This will be tbe box ;) .



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Offline Hi-Phibian

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Re: MM Phono Stage
« Reply #160 on: September 13, 2019, 08:33:18 PM »
With a traditional linear supply the bigger transformer tends to sound better and gutsier.  Soft recovery rectifier diodes are also worth using. 
The onslaught of why this canít make a difference will be in posts to follow soon but at least you are aware of the option now and you can decide to try it or not. 


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Offline fdlsys

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Re: MM Phono Stage
« Reply #161 on: September 13, 2019, 08:41:16 PM »


With a traditional linear supply the bigger transformer tends to sound better and gutsier.  Soft recovery rectifier diodes are also worth using. 
The onslaught of why this canít make a difference will be in posts to follow soon but at least you are aware of the option now and you can decide to try it or not. 


.

+100 on both.
The very best diodes here would be schottky. Very fast, zero turn-on noise so no need to silence the switch-on overshot with small caps. No caps, no stray LC resonances. The simpler, the better.
The four building blocks of the universe are fire, water, gravel and vinyl. Dave Barry
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Offline Prince

Re: MM Phono Stage
« Reply #162 on: September 13, 2019, 10:26:01 PM »
 :cool:

Phono Stage BOM for all the Cape Town Builders:
https://docs.google.com/spreadsheets/d/1VPLUlHavLgPNKaZPIcf9QYeuuhuut3b-sSbkTtDzQCo/edit?usp=sharing

-I did this to check what I already have in stock.

"F5 Amp Power + Pedal Power = F5 Pedal Power"

Online Ampdog

Re: MM Phono Stage
« Reply #163 on: September 14, 2019, 06:06:58 AM »
Aqualung,

I noticed this thread only now; did not read through the whole contents (see time - still going to bed, not up early!). So not sure whether someone commented on the fact that you also have a Quad 22 (phono stage).

Thus as a kind of aside, the performance of the single EF86 stage used for that can be noticably enhanced by replacing with a double triode - say ECC88 or such or one of many triode-pentodes available. This can include a.o. a sharp low cut-off feature to eliminate stuff below say 30 Hz or however low you might prefer (there is really not a whole lot below 30 Hz on records, while quite some rubbish might lurk. Such a feature is standard on all my R!AA stage designs).  Not to expound now, just mentioning for whoever might be interested. There are enough internal tie-points to neatly accommodate a somewhat more complex circuit.

As said: Just by the way.
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Online fredeb

Re: MM Phono Stage
« Reply #164 on: September 14, 2019, 09:55:44 AM »
With a traditional linear supply the bigger transformer tends to sound better and gutsier.  Soft recovery rectifier diodes are also worth using. 
The onslaught of why this canít make a difference will be in posts to follow soon but at least you are aware of the option now and you can decide to try it or not. 

+100 on both.
The very best diodes here would be schottky. Very fast, zero turn-on noise so no need to silence the switch-on overshot with small caps. No caps, no stray LC resonances. The simpler, the better.

Thanks for the advice guys ! I think that we ( I am at least ) , are first going to try the Muffsy PSU , which is part of the build . Perhaps we can try an alternate supply , can either of you make up a hand drawn schematic , or find a simile on the web ?

Aqualung,

I noticed this thread only now; did not read through the whole contents (see time - still going to bed, not up early!). So not sure whether someone commented on the fact that you also have a Quad 22 (phono stage).

Thus as a kind of aside, the performance of the single EF86 stage used for that can be noticably enhanced by replacing with a double triode - say ECC88 or such or one of many triode-pentodes available. This can include a.o. a sharp low cut-off feature to eliminate stuff below say 30 Hz or however low you might prefer (there is really not a whole lot below 30 Hz on records, while quite some rubbish might lurk. Such a feature is standard on all my R!AA stage designs).  Not to expound now, just mentioning for whoever might be interested. There are enough internal tie-points to neatly accommodate a somewhat more complex circuit.

As said: Just by the way.

Are you refering to me perhaps @Ampdog ? I'm interested (amd have Quad 22 pre ) , if you wish to expound ?
« Last Edit: September 14, 2019, 09:59:04 AM by fredeb »
...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts