[bluesky]

Hi to everyone in the Hagtech community

I am nearing completion of my Clarinet and Cornet 2 and would like to ask a couple of questions about parts selection.  So far I have chosen to use Mundorf Silver Supremes and Kiwame resistors as well as a couple of Obbligato caps from DIY HiFi Supply.  The Obbligatos look quite good in their new new copper cases and I will be interested to hear what they sound like eventually.

My first question relates to the 1N5821 diodes used in both the Clarinet and Cornet.  Can I safely substitute either MUR860's or 8A 1200V Stealth diodes that I have on hand?

The second question is about the C202 (L/R) and C204 (L/R).  I can source some cheap ceramic caps or go the whole hog with Jensens or Multicap, but is this worth it sonically?  Or is it really a case of wanting to have something exotic just to make me feel good!  

Thanks for any advice.

Bluesky
Brisbane, Australia

[hagtech]

Do not use cheap ceramic caps for the EQ.  They are very important..

jh

[bluesky]

Hi Jim

Thanks for this advice.  I will get some good stuff for these components.  

However, I would still like to know if putting some high speed soft recovery diodes in place of the 1N5821 diodes is appropriate and/or worthwhile for these.  To date I have not seen any comment on these in the various posts (but I may l have missed it).

Thanks

Bluesky

[hagtech]

Sure, but the diodes are already fast recovery Schottky types.

jh

[bluesky]

Hi Jim

Thanks for this information!  

It is just that I have the diodes on hand and it would be easier to use them than to buy another two sets of diodes when I already have some sitting in my parts bin doing nothing but waiting to be used in a project.  They were actually given to me by a friend for whom I did a bit of soldering for and I have been waiting for a project to use them in.

I really like the new Hagclock, I think I may have to get one for an old Pioneer PD-7700 CD player that my Dad gave to me.  Despite its age, it sounds very good indeed and a clock and a couple of caps and opamps in the right places would bring it up to modern standards.  Pioneer use their inverted "stable platter" transport and maybe this has something to do with the very high quality sound it produces.

Best regards

Bluesky

[hagtech]

Oh wait, I didn't check to see if your diodes were schottky or not.  They probably are not!  Because of the super high voltage rating.  Those were designed for switching power supplies and TV sweep circuits.

You MUST have Schottky types to get the super-low voltage drop.  Otherwise heater voltage will come out wrong.

jh

[bluesky]

Thanks Jim!

I will use the Schottky's!

Bluesky.

[andrew]

Hi,

 I tried some Stealth diodes in my Cornet as an experiment. I'd been suffering from noisy diodes and was trying to cure the problem. Perhaps I had a couple of bad batches of 1N5821s, I tried twoo separate sets, and I was never really comfortable with the noise, which on my system was making its way into the audio chain.

I saw exactly what Jim predicted, heater voltages too low, but it did solve my hum problem, with diodes in place the circuit is quieter and the background more inky but the sound is poor due to the low heaters. Unfortunately, to get the heater voltages back up you need to reduce the R on the heater filter, or increase the C. If the R is dopped the subsequent reduction in smoothing means the hum just gets through again.

I've been searching for replacements, perhaps Jim might have an alternatives for anyone who find the 1N5821 too noisy in their system.