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Old 11th September 2003, 06:27 PM   #11
Raj1 is offline Raj1  United Kingdom
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Default cheers dude

Cheers mate,

Just ordered the sowter transformers and some tubes...........


By the way from the datasheet I can see that B+ is connected to the white lead???

http://www.sowter.co.uk/specs/8650.htm

Also what are the suggested wattage values for the resistors?

R8, R9 and R10

R11 and R12

R4, R2 and R7 also similar positions for other channel?

I assume that the critical resistors for sound are R4, R2 and R7.......

What's the general preference here for types on the critical resistors, in the UK I haven't seen anyone selling Riken ohm's yet.....

There are bulk foils and metal films, I'm looking for a nice smooth, musical sound....

Have you got that scope yet?


Thanks dude for the service.....

Raja
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Old 11th September 2003, 06:43 PM   #12
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Hi,

Quote:
By the way from the datasheet I can see that B+ is connected to the white lead???
Yes, that's it. I prefer the one with the solder tags but that's just me.

R2 +R4 are gridstoppers and are in series with the signalpath, they should be good quality metalfilms, 1/2W would do.

R7 is the cathode R, I'd use a 2W resistor there.

The rest is in the PS I suppose 4W would do.

Check with Maplin or RS components for what they carry in those wattages, better to use a higher wattage resistor than needed since they usually withstand higher voltage better.

If you can find someone selling NOS Holcos then these should provide for smooth sound.

The bulkfoil are fine but expensive. They're often not available in more than 1W ( I think) but you can use them as gridstoppers if you find them.

Dale, Mills,Welwyn are some popular brandnames for resistors nowadays.

Cheers,
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Old 17th September 2003, 06:10 PM   #13
Raj1 is offline Raj1  United Kingdom
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Default pin 4 on socket

Hi Fdegrove,

My 3A5's arrived yesteday, as did the chassis mount sockets for them, however there is no solder tag on the sockets for pin 4, which is left with an empty slot. Given that I'm supposed to connect this to ground, have I recieved the wrong sockets, or is this standard practice?

Thnaks
Raja
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Old 17th September 2003, 06:50 PM   #14
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Hi,

Quote:
My 3A5's arrived yesteday, as did the chassis mount sockets for them, however there is no solder tag on the sockets for pin 4, which is left with an empty slot.
Uh?

Quote:
Given that I'm supposed to connect this to ground, have I recieved the wrong sockets, or is this standard practice?
It's definetely NOT standard practice for any socket I know of....

Want you need is a pair of standard 7 pin miniature socket (AKA pico 7).

Cheers,
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Old 17th September 2003, 06:56 PM   #15
316a is offline 316a  England
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Default Re: pin 4 on socket

Quote:
Originally posted by Raj1
Hi Fdegrove,

My 3A5's arrived yesteday, as did the chassis mount sockets for them, however there is no solder tag on the sockets for pin 4, which is left with an empty slot. Given that I'm supposed to connect this to ground, have I recieved the wrong sockets, or is this standard practice?

Thnaks
Raja
Hi Raj ,
Drop me an email via the system , I may be able to assist with some decent teflon b7g sockets .

316a
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Old 17th September 2003, 07:19 PM   #16
Raj1 is offline Raj1  United Kingdom
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Hi,

Just posted an email to the suppliers, lets see what they reply with.............

Thanks
Raja
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Old 26th September 2003, 09:37 PM   #17
Raj1 is offline Raj1  United Kingdom
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Hi,

Recieved the bases with the correct number of tags from tube shop, they were okay and understanding about it and sent replacements quickly.....


Using a maplins 100va kit, I've wound a heater supply for the AZ1, using 0.9mm copper wire (supplies around 2 amps), reading at the transformer with no load is 4.1v.

Calculation for the winding was to take number of volts req'd and multiply by a factor of 4.16. This give 16.64 turns, also adding 1% per 10va requirement so around 17 turns.

Hopefully I shouldn't get any voltage sag upon load of the az1, which requires 1.1 amps.



I've also wound another secondry for the regulated supply to the 3a5's, which reads 5.7v at the transformer.....

In any case nearly all the parts are now here, just waiting on the AZ1.........

I have decided to make as much of the circuit on bread board as possible, rather than just go point to point and have wires that are untidy all over the place......

I've made the heater supply and I'm reading 2.87v at the rails after the regulator with no load..........

The B+ supply is almost complete on bread board also.............
.

I plan on having the mains transformers in one corner of the machine, over and around the generic power supply. The AZ1 rectifier will sit in the centre of the top cover of the player, albeit towards the back as the transport occupies the front......

The 3a5's wil be mounted next to each other on the top cover, very close to the output pins of the dac, in order to keep signal wiring as short as possible.

For signal wiring I am using 0.5mm silver wire, and I'm using single strand copper wire - stripped from 30a mains wire to wire the B+ on the bread board.

I'll probably use the silver wiring for B+ connections to the tube pins also.

With reagrds to the choke is this best kept away from the mains transformers and also the output transformers???

In general what circuitry do I need to avoid when mounting transformers and also running mains and signal wiring thru the cd player, that give hum and sound problems???

Thanks
Raja
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Old 27th September 2003, 01:01 AM   #18
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Default Re: Re: pin 4 on socket

Quote:
Originally posted by 316a
assist with some decent teflon b7g sockets .

316a
Nice sockets. I think I'm gonna get some more next pay.
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Old 27th September 2003, 01:09 AM   #19
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Hi,

Quote:
Nice sockets. I think I'm gonna get some more next pay.

Need novals too?

I wouldn't mind trading some of my teflon novals for B7Gs....

Cheers,
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Old 27th September 2003, 01:34 AM   #20
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Quote:
Originally posted by fdegrove
I wouldn't mind trading some of my teflon novals for B7Gs...
The only B7G's I have are from 316a, and his prices are very reasonable IMO, but I'm interested in your novals. Will email.
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