Integrated Pre-amp with Line Driver + Phono + TVA's

What people are working on at the moment
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Toppsy
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#106

Post by Toppsy »

Wow guys a lot has been posted since I last logged on Friday. I'll have to read and inwardly digest it all.

Andrew,
thanks for posting the veroboard layouts that will make life much easier for me. I am presently searching through the RAPID catalogue for all the components so I can add them to my spreadsheet and get an order placed. I am also intending to include all schematics and your veroborad layout in the spreadsheet.

Nick, you memtioned the 7H maplin chokes would be on their limit. There are other chokes on the Livinginthepast web site. Are any of these more suitable?

Colin
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#107

Post by simon »

Andrew wrote:For my part, I have to say there is absolutely no reason Simon or Colin has to follow what I suggest, I don't fell ownership of this, merely offering to help with their projects and perhaps learn a little along the way.

It's your build Colin, Simon....you must decide what you like.....

cheers,

-- Andrew
Wouldn't have it any other way Andrew :D. I'm really grateful that you're interested enough to put so many hours in to this for myself and others' benefit. This is the spirit of DIY I think, and is why this is a good place to hang out.
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#108

Post by Darren »

izzy wizzy wrote:
I am new round here so at present, I only feel comfortable telling people some areas they might want to think about. If they want to ask me why in return, then I'm happy to say so. The whole topic of power supplies is a huge one IMHO and it's possible to go on and on about something and it not being what someone wants to hear. I suppose I was dropping hints and not wanting to derail an existing design or devalue anyones else's suggestions.



Stephen
Don't let that stop you, some new, or not so new, as the case may be, lines of thought would sure be welcome around here.
Not everyone thinks the same and unfortunately those that don't follow the masses tend to take a back seat.

Speak up....!
Last edited by Darren on Sun Jan 13, 2008 7:34 pm, edited 1 time in total.
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#109

Post by Andrew »

Yep, there's always more than one way to solve a problem, so the more opinions, ideas and designs the merrier, as far as I'm concerned...

cheers,

-- Andrew
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Toppsy
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#110

Post by Toppsy »

Nick Wrote
Hang on, you are going to be pulling 100ma B+, those maplin chokes are going to be on the edge at that.
OK. Checking out the Livinginthepast web site I'll use the VT1131 chokes. These are similar to the standard VT495 but 200ma.

Regards

Colin
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#111

Post by Andrew »

Hi Colin,

Does help with the layout?

cheers,

-- Andrew
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Toppsy
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#112

Post by Toppsy »

Andrew,

that's splendid. Ta very much. :D

Colin
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#113

Post by Andrew »

-- Colin,

You'll still need to get the R and C values off the other post..but it should be clearer.

cheers,

-- Andrew
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#114

Post by Andrew »

Hi Colin,

I found the cause of some hum I was getting that had originally led me to believe the output cap on the reg was too small (C1) above, despite the fact I could see no hum at all on the scope....anyway it wasn't the reg boards, it was a msall amount of ripple on the DC regulator for the heaters getting coupled into the cascode. I raised the heaters on the cascode and viola its gone, so 470nF which I listening to now sounds really fine :D

cheers,

-- Andrew
Last edited by Andrew on Thu Jan 17, 2008 8:54 pm, edited 1 time in total.
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#115

Post by Andrew »

And Mrs Toppsy will be most pleased since 470nF film caps at that voltage are a dam sight cheaper, for the same quality, than 4u7F :D

cheers,

-- Andrew
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Toppsy
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#116

Post by Toppsy »

Hi Andrew,

That's good news. I think some mundorfs are due then for those 470nF caps.

Cheers

Colin
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#117

Post by Andrew »

Well I would try generic cheapo ones first, although they do close the AC loop for the C3g so a nice cap might well be a good thing here...

-- Andrew.
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Toppsy
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#118

Post by Toppsy »

Andrew,

I will be using WIMA MKS4 400V caps for all the 470nF caps initially and buy 2 mundorf 0.47uF silvers once I can put enough components together to justify an order to partsconnexion.
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#119

Post by Andrew »

R10 in the above schem needs to be 3 watts, that's the 47k resistor in your design, the one from the ADJ leg of the reg, but to its right, which goes to ground.

cheers,

-- Andrew
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Toppsy
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#120

Post by Toppsy »

Simon Wrote
I'd be interested in the price they quote you Colin "for future reference"
This of course refers to the one off special toriod from Antrim transformers. Spec's:

Primary Windings: 0-230V @ 50Hz
Secondary Windings: 0-220V @ 0.17A rms
0-9V @ 2A rms
0-6.3V @ 1A rms

Approx Dimensions: 91mm x 44mm
Approx Weight: 1.2kg
Mounting method: central M5 clearance in a potted centre. Unfortunately cannot currently encapsulate this size TX.

Price 1 Off: £55.00 + £10.00 carriage (DHL) + £2.41 Paypal fee = £67.41

delivery 7-14 days from receipt of payment.
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