Paradise Builders

[pdul]

My Fairchilds were hopeless too, in the same way, and i bought it from RS.
Then i bought one more batch Diotec brand from Conrad in Germany, and it was much better matched.

[FdW]

In the Mpp thread I have posted this Mpp about grounding and connecting the player to the preamp.

[Joachim Gerhard]

Great work, Frans and Ricardo. I have not reviewed it in detail. Simply no time.

[hesener]

As announced in the group buy thread: All parcels are out the door. So I would like to ask all builders to share their insights, experience and of course listening impression !!!

With 300 essentially identical phono stages to be built around the world, this could be a great source of insight into many things, like cartridge - preamp interaction, component choice, arrangement in the case, etc etc - Looking forward to all the sharing! And of course, in case of issues or problems just post here and I am sure the team will be happy to support.

However, we all want this thing to work at first turn-on, so please read the assembly guide carefully , there is a lot of experience from the beta builders already there.

Please note: There are various references floating around, to R2 and R3 - both are the same except the input offset trimming which is implemented in the R3, so no worries.

Happy building!

[Joachim Gerhard]

Thanks Alfred.

[FdW]

Great job Alfred!

[Nick77]

Originally Posted by pdul

My Fairchilds were hopeless too, in the same way, and i bought it from RS.
Then i bought one more batch Diotec brand from Conrad in Germany, and it was much better matched.

Where are the matched transistors located? Are they just the 8 spots in brackets flanked by the 6800 caps?

[Bksabath]

Originally Posted by Nick77

Where are the matched transistors located? Are they just the 8 spots in brackets flanked by the 6800 caps?

Just look at build guide
Circle around imputs and current mirrors yes?

[Bksabath]

On matching
I tried litle (big) Atals unit and mesure low
Tried curve tracer (but don't trust it) and Example get 563
Tried circuit published on build guide and mesure example 555

Litle circuit there is prety good.....

[LouderIsBetter]

Originally Posted by Nick77

Where are the matched transistors located? Are they just the 8 spots in brackets flanked by the 6800 caps?

The answer to your question is on the first page of the assembly guide. The most important match is the 8 transistors at the input gain stage (these should also have the highest HFE). It's also important to match the transistors in each current mirror. But not necessarilly one mirror to the other, although I'm sure that won't hurt.

Mark