• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Strip board project completed.

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
Just for fun here is a strip board project just completed!
I just wondered what I could power with a laptop power supply.
So here are the boards, they were modified through the project.
:)

Regards
M. Gregg
 

Attachments

  • DSCN0406.jpg
    DSCN0406.jpg
    102.4 KB · Views: 1,074
  • DSCN0418.jpg
    DSCN0418.jpg
    29.3 KB · Views: 1,021
  • DSCN0417.jpg
    DSCN0417.jpg
    28.6 KB · Views: 992
  • DSCN0419.jpg
    DSCN0419.jpg
    27.5 KB · Views: 978

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
Start of the enclosure build.

Glass front plate and input phono sockets fitted.:)
I will post more shortly.
 

Attachments

  • DSCN0428.jpg
    DSCN0428.jpg
    26.4 KB · Views: 189
  • DSCN0425.jpg
    DSCN0425.jpg
    25.1 KB · Views: 201
  • DSCN0424.jpg
    DSCN0424.jpg
    25.3 KB · Views: 292
Last edited:

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
ECC88 Aikido section in place with 350V to 250V regulator. Inverter section installed with soft start, DC heaters lifted using Recom inverter isolation. Staged heater start circuit with current limit and thermal "solid state fuses". HT switched from heater circuit by Triac.
 

Attachments

  • Picture 029.jpg
    Picture 029.jpg
    23.9 KB · Views: 595
  • Picture 036.jpg
    Picture 036.jpg
    22 KB · Views: 619
Last edited:

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
What's all that about?:magnify:

The input selector uses a decade counter with debounce circuit, this drives the relays on the input board. Each output from the decade counter drives a different colour LED all mounted under the glass diamond on the front. So you can link the colour to the input selected. IE green Ipod, yellow CD, red tuner, ect. Just a bit of fun the glass changes colour.
:)

Regards
M. Gregg
 

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
OK.

I have "created in p. point and converted to jpeg" the input selector section schematic.
I must admit I don't know why anyone would use a rotary switch when you can position a single push button any where on the chassis and have the relay board next to the phono socket inputs. The 18K for the reset is not critical, however if the value is to high or low it will effect the current drain from the chip or not allow a "0" for the count. The 0.1uf from supply to reset ensures that the selector always starts at output "0". It is easy to modify for as many inputs as required!You could use output "0" as mute at start and move the inputs to output 1,2,3,4 etc.

Regards
M. Gregg
 

Attachments

  • Input Selector comp doc.jpg
    Input Selector comp doc.jpg
    45.5 KB · Views: 319
Last edited:

M Gregg

Disabled Account
2010-06-28 11:04 pm
UK
Sorry,

I said I would post some of the circuits.
Here is the HT inverter it is very simple and with a filter it powers the Aikido section the regulator and the EM80's. I found it interesting because it uses a Tx that is easy to make. Also it does not supply HT if no load is connected, so a heater failure turns off the HT.
Wind the HT coil first then insulate with tape and wind LT on top(Spread the windings across the Bead)!
Don't be tempted to "bolt through the bead with a steel pin" to secure it! Use a plastic pin or tyrap.
I know some people will say "regulation". It works well for me there is more noise from the regulator than the inverter! (mV)
:)

The Inverter circuit was modified from this link. I found the reg they used to be of little use! Shorts take out the transistor. The one further back in the post Maida works well!

Inverter HT PSU


Regards
M. Gregg
 

Attachments

  • Inverter Txa.jpg
    Inverter Txa.jpg
    13.8 KB · Views: 289
  • Inverter circuita.jpg
    Inverter circuita.jpg
    31.5 KB · Views: 279
Last edited: