[tubesforever]

I mentioned to Jim in a couple of posts that my experience with several other tube and solid state phono sections leads me to believe that the RIAA curve in the Cornet 2 could be better, at least in my Teflon hot rodded Cornet 2. 

Jim supplied me with the tools to research curves I might like to explore.  Thank's Jim!

So after hearing about his success with the new C3 design and its successful RIAA curve I decided it was time for me to tweak again. 

I pulled out every one of my spare K40Y9 0.047uf PIO caps and double checked their measurements.  Then I took a set of Teflon FT-1 0.010uf caps that Pat OMalley had sent to me as a gift a couple years ago.  Thanks Pat!

I took a pair of 0.0493 PIO caps and paralleled the teflons.  I am sitting at 0.0593 now for the lower RIAA cap set at C202 right and left.  What I am hearing is more of the rich warm sound I heard with my Fisher tube phono, the George Wright signature phono stage I hot rodded for Jim Koska,  and the Bedini 6677 solid state phono section which defines the ultimate RIAA curve in my book. 

IMO its good to try these little adjustments.  While the 0.0593uf is too warm for my tastes, its a step in the right direction in terms of warmth and bass response.  I will continue to experiment and see if I can find a better match for my system.  I suspect that 0.0550uf will be my next trial and then 0.0510uf.

Jim mentioned that you could build a switch for your Cornet 2 and have selectable RIAA cures.  I might try to do a three way switch with 0.047, 0.0510 and 0.055 and call it good.   Like the loading switch on my Piccolo I can go warm for the DG albums and light for the RCA's.  It will be fun to have this level of selection available. 

Remember Jim Hagerman made me do this.....darn that guy! 

And to those that feel their C2 sounds just a little bass shy, check the heater voltage first and then add a little more capacitance at C202 right and left.  A little dab will do you!  0.0510uf (510 nf) will warm things up for sure.


Cheers!

[GRD]

An additional suggestion for anyone interested.  Buy Jim's Inverse RIAA board and use it to check you phonostage vs source.  Eg.  Hook up your CD player to the I=Riaa through the Cornet and listen.  Then compare to the CD player alone.  By ear you'll notice anything of merit.  If you're a tweaker, you'll always wonder if the RIAA curve in you phono stage is accurate.  This is a simple way to check by ear.

[tubesforever]

Yes this will work as advertised.

Here is a follow up to the RIAA caps on the Hagerman Cornet 2.  First, I am still spinning the 0.0593uf values.  I played some of my beloved Van Karjian DG albums tonight and the new low end RIAA value seems nearly ideal for the job.

Bill, the bass was eviscerating!

This is superb by the way because before with the 0.047 PIO caps I was not hearing the bass drums or the Cellos and string Bass.

I think the flutes and clarinets sound a little syrupy, so I do think that trying to hit 0.055 would be my next test point. 

The more I listened tonight the more I realize than many LP labels never followed the RIAA curve.  Only RCA is faithful there.  So I think I will do a three way selector switch of 0.0575 uf, 0.0550 uf and 0.0525 uf. 

I need to be able to dial in the right eq for all these different EQ'd albums I have collected.  Getting the sound 80% right just doesn't get me excited.

As a final aside, for the 100 nf cap I am trying a Russian Silver Mica cap that is very very smooth.

Someone here sent me that cap a year ago.  Was that James, Bob or someone else?.  I really like this cap.   The highs are very clear and extended and avoid the sibilance I hear with other brands of silver mica.  This is not a night and day difference.  I could live with the K40y9's forever. 

The Russian silver Mica is a bit more extended.  I liked it with my Christmas bell music.  The Rusian silver Mica caps are a good fit for the Foster Ribbon tweeters I run in my speaker system.   I get better air up top.

Jim can you put in a RIAA selector switch into the C3?

[hagtech]

Jim can you put in a RIAA selector switch into the C3?

Hey, that's a very good idea.  Such a perfect opportunity!

jh

[tubesforever]

Jim you are one heck of a designer with or without an RIAA switch.

For those reading along with my musings I think I will be happiest around 0.054 uf instead of 0.047 uf.  I just need a little more Cello and Viola in my orchestral stuff.   

The sound is closer to where I want it.  I like classical and the DG albums are my preferred poison.  The RIAA curve is great for this label.  It matches what I remember from my Bedini 6677 and John Bedini was very proud of his RIAA implemented in the 6677 dual mono preamp.

One other thing.  The incoming signal cap is 0.10uf.  I have used a lot of caps here.  Today I tried taking out the Russian teflon FT-3 0.10uf 600v cap and tried the FT-2 0.10uf 200v cap. 

Well the results were disappointing.  So I am back to the FT-3 in this position.  I get superb dynamics without any collapse in the sound field.  Its the best I have heard in my system. 

So for someone using FT-3 caps, can you try a pair in C203 right and left.  Also, if you can confirm the 0.0540 uf cap as working right in your system I would appreciate the confirmation. 

You only need to try the 0.054 uf cap IF you feel your bass is a little shy.  If your bass is robust do not touch that 0.047 uf cap!
Thanks in advance for for confirming my insanity!

[tubesforever]

An update to improving the equilization on your Cornet 2.

I wired in a 4 pole three selector switch.  I used 0.00068 uf for position 1 (680 pf) , 0.001 uf for position 2 (1000 pf), and 0.00136 uf (1360 pf) for position 3. 

I have to say that Jim H is nearly ideal about these capacitor values.  The 680 pf cap makes for a brighter sound and this does work really well for the EMI and FFRR recordings where the highs had seemed rolled off, the 1360 pf cap works nicely for some of my Columbia 6 eyes that were so dang bright that you wanted to run for cover.

Its great having a switch right up front to dial in the equilization. 

I did change the 0.047 uf cap to 0.054 uf in order to get more violin, viola, and cello details.  I think the Russian teflon caps conspired to make the lower midrange a little too polite.   Now the sound has a most pleasant growl in the mid bass.   Trombones and french horns sound just like they should.

I tried a lot of values between 0.047 and 0.062 and the 0.054 seems the best compromise for the teflon C2 I built.   If your C2 is not bass shy then don't try this tweak.

The 680 pf, 1000 pf, and 1360 pf switch is sublime.  I am having a great deal of fun listening to the EMI recordings I felt were too rolled off. 

Jim, I am using a silver/brass non-shorting selector switch and I get no pops or clicks at full volume switching on the fly.  I hope you can find a decent quality non-shorting pcb mount switch for the C3.  You won't need to worry about pops.

Happy New Year!

[hagtech]

no pops or clicks at full volume switching on the fly

True, once you get all caps charged up to value.  It takes a mere moment to get the cap up to dc voltage.  That's the thump.  If you charge up all 3 caps before you start listening, they'll hold a charge for a long time before they bleed away (leakage), where you can switch back and forth without pops.  Try again after 1/2 hour and I bet you hear a thump.

jh

[tubesforever]

Yep, I got some mild pops tonight going from the powered up cap switching over to a non powered cap. 

It was not a tweeter killing pop but it was definitely something to consider if you play at high volumes.

Thanks Jim!

BTW I ended up with 0.0009uf, 0.001 and 0.00135 for the RIAA caps.  I will look for something around 0.0008.  0.00068 uf was a little overly bright in my system even for the laid back EMI's. 

Jim I had absolutely no idea that such minute changes in UF would produce this level of equilization swings.   For grins I put in 0.00032 uf and it was so bright I thought it was technicolor. 

Thanks for the recommendations by the way.  My C2 sounds better than ever with this switch.  The Beatles Parlaphone Abby Road did real well with the 0.00090uf caps.  Those albums were mastered from the original or safety copies of the EMI tube R2R decks at Abby Road studios.