HK330c vs. 430

[Soundork]

I own both HK330c and a 430. They are all original.

I would like to know if others that either own both or heard both receivers think that in terms of sound they have the same signature, but the 330c is capable of resolving more detail?

Thanks in advance.

Best

Soundork

P.S. I listen in my smallish office approximately four feet away from speakers at 50dBA.

 

[Blue Shadow]

do you even have to turn the unit on to get 50dB out of the speakers?

 

[mhardy6647]

1) The 430 is a markedly superior piece of hardware to the 330C -- but you may or may not prefer it.
2) The only fair comparison would have been both receivers when new. Forty years on, you're hearing the differences of two different designs that may have differentially deteriorated in the interim. I would opine that, until and unless both have been restored to an identical level of functionality (e.g., at the least, all electrolytic capacitors in the p/s and amplifier sections replaced with the same brand and equivalent types of of electrolytics), comparison is going to be fairly meaningless.

Listen to the one you prefer.

Scan0012 by Mark Hardy, on Flickr

 

[Soundork]

do you even have to turn the unit on to get 50dB out of the speakers?

I have very good ears.

 

[mhardy6647]

https://www.osha.gov/SLTC/noisehearingconservation/

That's fourteen orders of magnitude (speaking of good ears -- our species has good ears).

 

[Soundork]

1) The 430 is a markedly superior piece of hardware to the 330C -- but you may or may not prefer it.
2) The only fair comparison would have been both receivers when new. Forty years on, you're hearing the differences of two different designs that may have differentially deteriorated in the interim. I would opine that, until and unless both have been restored to an identical level of functionality (e.g., at the least, all electrolytic capacitors in the p/s and amplifier sections replaced with the same brand and equivalent types of of electrolytics), comparison is going to be fairly meaningless.

Listen to the one you prefer.

Scan0012 by Mark Hardy, on Flickr

Thank you for your reply.

I want to emphasize: Both sound identical, just the 330c resolves more detail at the volumes I listen music to, which never exceeds 60dB's. At louder volumes the 430 has the edge, but I would like to keep the discussion to volumes that I am listening at.

So, the question was/is: At volumes no more than 60dB, does the 330c sound identical to the 430, but with the ability to resolve more detail?

 

[mhardy6647]

Thank you for your reply.

I want to emphasize: Both sound identical, just the 330c resolves more detail at the volumes I listen music to, which never exceeds 60dB's. At louder volumes the 430 has the edge, but I would like to keep the discussion to volumes that I am listening at.

So, the question was/is: At volumes no more than 60dB, does the 330c sound identical to the 430, but with the ability to resolve more detail?

Based on your qualification, they don't sound identical. They exhibit audibly different performance to your ears at very low output power levels.
That's fine; again, listen to the one you prefer.

It is also impossible to speculate as to whether the differential would have been observed when both were new -- you might (???) be able to get some insight into that if you could find Stereophile-style quantitative reviews of the two components. Julian Hirsh style tests likely won't tell you much. Look for plots of "THD" (usually actually THD + noise) as a function of ourput power for the two receivers. If you find them, compare the quantitative performance, at output power levels of 100 mW or less.

IF published test data exist, you should be able to find them at www.americanradiohistory.com

Their scanned archives of Audio, Stereo Review, and High Fidelity have been OCR'd and are searchable.

https://www.americanradiohistory.com/Audio-Magazine.htm
https://www.americanradiohistory.com/HiFI-Stereo-Review.htm
https://www.americanradiohistory.com/High-Fidelity-Magazine.htm

EDIT: The loudspeakers you're using will have an effect too. If nothing else, the output impedance ("damping factor") of the two receivers is probably not identical, thus their response to any given load's impedance curve may well differ. This might have been true when they were new, it is almost certainly true after 40 years. It is safe to assume that most or all of the myriad electrolytics in both receivers are not "up to spec" (this includes their ESR - 'equivalent series resistance' as well as their capacitance values) after four decades.

 

[Blue Shadow]

I don't recall doing specific tests like that back when selling HK. The soundroom, the only place where the two would be pitted against each other was a large room with lots of speakers and the 430 would have more oomph, a full 5 watts per channel. These were new then.

I have recapped two 330c receivers and they were prior to the recap, a great push a button and the radio is playing nicely, system in the soundroom I have now. Much easier that firing up the main rig.

If they sound the same except better resolution on the 330 it is probably because the house sound is there and the 330 is either in better condition or the lesser amount of stuff n the box is good for resolution. We sold a lot of 330s.

I would rebuild the 330c and call it a day. Seems to do everything you want and if you have read a bunch of ak it is frequently the smaller units that sound better in many manufacturers lines. Mostly talking the monster receivers vs. the smaller ones, not the two at the beginning of the line up.

 

[Soundork]

Based on your qualification, they don't sound identical. They exhibit audibly different performance to your ears at very low output power levels.
That's fine; again, listen to the one you prefer.


EDIT: The loudspeakers you're using will have an effect too. If nothing else, the output impedance ("damping factor") of the two receivers is probably not identical, thus their response to any given load's impedance curve may well differ. This might have been true when they were new, it is almost certainly true after 40 years. It is safe to assume that most or all of the myriad electrolytics in both receivers are not "up to spec" (this includes their ESR - 'equivalent series resistance' as well as their capacitance values) after four decades.

You are absolutely right. Technically they do not sound identical.

I have a second 330c unit which I am going to refurbish after my school semester ends. It has a failed transistor in its phono stage, but everything else sound exactly identical to the unit that is healthy. That was my exactly my logic behind my question: If I had two untouched 330c's that sound identical, then the 430 must be off, which might be the case. Thank you for pointing out the role of speaker impedance.

 

[Soundork]

. We sold a lot of 330s.

.

I remember you saying that from reading past posts on the subject.

The plan is to eventually refurbish both 330c's I have. I have the BOM already. Here is how I'd like to approach this:

1. The unit with the failed phono stage gets its phono stage fixed and recapped first and compared to the one that is still healthy.
2. The recapped unit gets semiconductor upgrade and then compared to the healthy one.
3. The recapped and upgraded unit gets to have its passive elements such as, resistors upgraded and compared to the healthy one again.
4. Refurbish the healthy one with the upgrades that make sense i.e. if "the sound" changed in a way I didnt like, I am not going to implement that change.

It would be interested project, but going to grad school while working interferes a lot with my hobbies...

 

[Blue Shadow]

@dlucy rebuilds them saving only the chassis it seems. He has documented much of the work but don't know if he did stages.

We compared a 330c that I had recapped with one that I had just picked up to replace the earlier unit, now at a friend's house. No one had a preference, there were some sonic differences and one picked out the recapped unit base on his knowledge of what to listen for in a recapped unit. Recap was just that a recap, no other electrical devices were harmed in that procedure. The second 330c got a recap and is now relaxing in Columbus, OH area and being enjoyed by a new owner wanting to hear is records again.

 

[Soundork]

I dont want to dilute the discussion with what I want or need to do.

I am soliciting an honest opinion with regards a comparison between the HK330c and 430.

This discussion has led me to believe that there is something wrong with my 430. I looked at the schematic and it is virtually the same preamp and amp. There are two capacitor and one transistor values that have been changed. I am pretty sure that the latter doesnt have any effect on the sound, I cannot tell about the former off the top of my head. No time for the analysis right now.

 

[wmgwizard]

I believe the 330 series is cap coupled and if so many people believe these are very detailed or tube like in their sonic presentation.

I do not believe the 430 is cap coupled but it does have twin power supplies and 20% more power. The detail may not be as great but it should "punch" a little harder.

 

[dlucy]

Looking at the actual schematics, the main amp board design in both the 330c and twin powered 430 is identical. They use slightly different output transistors, but that would not change the sound.

The preamp boards are also nearly-identical with the only significant difference is one uses NPN pair in the first transitor stage and the other uses a PNP pair.

So the only big difference between the two is the twin powered 430 has two power supplies (one for each channel) and the 330c has only one power supply that is shared by both channels.

And both the 330c and all the subsequent models, including all the twin powered series, are neutral sounding due to direct-coupling as opposed to all the prior models being cap-coupled (e.g. 330A, 330B, 230, 520, 720, etc.). Now THAT makes a huge difference in the sound coming out of each.

 

[The Fuxtor]

330c wasnt cap coupled, I believe the the a , & b variants were.

 

[dlucy]

330c wasnt cap coupled, I believe the the a , & b variants were.

Doh! You're absolutely right.

 

[Soundork]

Looking at the actual schematics, the main amp board design in both the 330c and twin powered 430 is identical. They use slightly different output transistors, but that would not change the sound.

The preamp boards are also nearly-identical with the only significant difference is one uses NPN pair in the first transitor stage and the other uses a PNP pair.

So the only big difference between the two is the twin powered 430 has two power supplies (one for each channel) and the 330c has only one power supply that is shared by both channels.

And both the 330c and all the subsequent models, including all the twin powered series, are neutral sounding due to direct-coupling as opposed to all the prior models being cap-coupled (e.g. 330A, 330B, 230, 520, 720, etc.). Now THAT makes a huge difference in the sound coming out of each.

Thank you, Doug.

I still think that it might be C404. Or most likely something wrong with the unit.

I wouldnt call 330c and 430 neutral, but I have heard in the past that the 330A/B are warmer sounding and now I am curious....

I do agree that the 730 is a very neutral sounding receiver. I have two of them, they both reproduce as much detail as the 330c and at higher volumes, of course.

 

[dlucy]

Thank you, Doug.

I still think that it might be C404. Or most likely something wrong with the unit.

I wouldnt call 330c and 430 neutral, but I have heard in the past that the 330A/B are warmer sounding and now I am curious....

I do agree that the 730 is a very neutral sounding receiver. I have two of them, they both reproduce as much detail as the 330c and at higher volumes, of course.

Yep, I like my 330C, too.

The outstanding difference between cap-coupled and direct-coupled is warm-sounding versus more-neutral-sounding. That doesn't mean your direct-coupled sounds neutral to you, it just means the same design with output caps will sound warmer. Could be very little difference, could be a lot. Designs will vary and ears will vary. The differing characteristic is warm versus neutral, but not necessarily big or bad, just different.