[Bobzilla]

poty,

I am injecting a 1Khz. square wave sourced from a Heathkit IG-5218 through a Hagerman RIAA2 (that's depicted in the picture) at .02V p-p. (Top trace) The bottom trace is the output at 2V p-p.



 The output of the RIAA2 is nearly a square wave, showing a slight slant owing to the reverse equalization.
 I think I've made a gross error in component placement. Mistakes happen. I just haven't caught it yet, nor have I had an extended opportunity to concentrate on it. This is a busy, social time for us and we all understand the penalty one pays for withdrawing from the family during these times.
 It's also most enjoyable! We recently caught Chris Isaak.
 Live Music.
 Ya gotta love it!!!
     

[hagtech]

Do you have the tubes in the  right sockets?  I seem to remember similar waveforms when an 12AU7 was accidentally placed in one of the 12AX7 sockets.

jh

[poty]

poty,
I am injecting a 1Khz. square wave sourced from a Heathkit IG-5218 through a Hagerman RIAA2 (that's depicted in the picture) at .02V p-p. (Top trace) The bottom trace is the output at 2V p-p.
 The output of the RIAA2 is nearly a square wave, showing a slight slant owing to the reverse equalization.

Slight slant after the equalization??? -20dB in the low-frequency, +20dB in the high-frequency! The form should be greatly affected!!!

[jameshuls]

Could it be that the test equipment requires calibration? From what I perceive from poty's comments, the expected square wave is wrong for both the Cornet and the iRIAA.

As for the lack of Bass you mentioned, that could be off-value caps in the RIAA section of the Cornet. I understand the correction curve is very sensitive to the value of the caps used.

Just my thoughts...

[Bobzilla]

 When I screw up, I usually do it as well as I possibly can. I also make that same mistake in both channels. Matched no less.
 Poty hit it, As did jameshuls.
 The problem began late one evening when I ordered the components for the Reverse RIAA filter. Instead of 60.4 and 536 ohm resistors I ordered 60.4k and 536K. I then slapped it together in short bursts, never giving it the attention it deserved.
 "It's a tiny, passive filter ... what could go wrong?"
 With the filter corrected, it confirmed that the Cornet2 was fully functional. Scope shots are excellent, noise is below anything my limited test gear can ascertain. I burned it in for a few hours and then placed it back between the Shure V15VxMR and the Clarinet.
 It still sounds light in the lower registers but I feel certain that the reason for this is ahead of the Cornet. Correct me if my reasoning is wrong but, I think if a cartridge sits unused for a long period of time, the dampening around the cantilever can loose much of its elasticity. If this is true, I think it would (depending upon degree of degradation) primarily affect the largest movements.
 It's time for an order to Jico.     
   
 

[Brinkman]

If you haven't already, I'd spend some time with the vinyl engine calculators and double-check my VTA/cart alignment, VTF and tonearm/cart compliance.

Do you have any test records?

[david62]

So,A old stylus cantilever can limit the low bass response?

[Bill Epstein]

I'm skeptical. There are some really old cartridges in use by collectors that are celebrated by them. Further, bass weight is a hallmark of the Cornet.

Look at filament voltage and or a misplaced resistor value creating a filter with it's attendant cap.

Or maybe it's just break-in

[Bobzilla]

 I've now had an opportunity to bring my cartridge/stylus back to life and I can state that this Cornet2 is, in a single word... Superb.
 I wouldn't characterize its sound as "tube like". That term to me, is older PAS, Fisher, SP3, etc. It certainly wouldn't be called "etched or hard". That's reserved for the less refined solid state designs typified by the PAT4/5, nearly all of the JVC, Sony, Pioneer, Kenwood, and to a lesser degree, some of the more polished silicon products from Mcintosh, Audio Research, and Mark Levinson.
 The Cornet2 is an excellent compromise between the two extremes. It's also amazingly dynamic. One of the attributes of the Cursio Daniel was the sound (similar to the Cornet2, a good thing) but it wasn't nearly as dynamic or "alive". That is where the Cornet2 really scores!
 If you need a new phono amp, (and since most newer amps or receivers omit this circuitry, you may very well need a new phono amp) give this Hagerman product consideration. Built totally stock it will sound great, spice it up and you will be rewarded!!             

[david62]

Nice to hear such a rewarding review after building it yourself.How is the low end now?Are you using  new or old tubes?Enjoy.

[Bobzilla]

 Yeah david62, the tonal response seems now very well balanced. Smooth, revealing and musical. It's a completely different sound than what came through upon first putting the V15VxMR back in the grove.
 Bill, I understand your skepticism, and I'm no expert in this regard, however, the sound change was far from subtle. I know many older cartridges are praised but I'm not positive that the cartridge body contains a significant amount of exposed to the atmosphere damping material. I believe the top of the replaceable Shure stylus cantilever is surrounded by a "damping material" to control resonances.
 I'm just speculating.
 I do recall that many years ago Decca was having problems with their cartridges in the Los Angeles area because of the smog effecting unnamed internal components. There were also similar difficulties, also in LA, with a tone arm (don't recall the name, it was short lived) that used tiny conductive pins moving through four circular troughs of mercury to lower the perceived physical resistance of the pivot!
 Again, I'm not an expert.
 Be it the dampening returning to normal or the burning in of the electronics, the sound has markedly improved.
 




   

[david62]

Good to hear that you are enjoying your tweaked Cornet2.Did you get a new stylus or a new cartridge?
Dave

[Bobzilla]

 No, nothing new.
 The Shure is sounding good and the stylus should have a lot of of hours left. I may order a new Jico replacement soon to both have a spare, and to be able to compare the SAS to the Shure while my original is still in reasonably good shape.