dlucy's guide to Harman Kardon minimalist series 230A, 330, 330A, 330B B-1, 330B B-2, and 330C

[dlucy]

The third era of solid state stereo receivers from Harman Kardon centered around the 330A and 330B and the clones made by Roland and Soundcraftman:



This thread is a guide to those models, their specs, and pointers to schematics and restoration threads for each. If you have additional information on any of these models, send me a private message and I'll get your info inserted into the right spot in the top posts.

I'm calling this era of HK stereo receivers the "minimalist" era... because that kinda fits their looks. If someone has a better name for this ear, let me know.

This era is identified by the change from the mostly-black, all-dark face plates of the prior "Nocturne" era to a very simple, silver-and-black, plain-lettering look.

Model numbers were numeric digits (e.g. 330) instead of the prior era's written-out numbers (e.g. “Three Thirty”).

I lump the models in the era in three waves of models:

• Initial wave of follow-ons from the Nocturnes. This includes the 230A and the 330 (all numbers, no trailing letter). These were manufactured in the USA.
• The second wave started with the 330A, continued with the 330B... and then the 330A's came back to life as 330B B-2 series. These were manufactured in Japan and Taiwan.
• The final wave in this era is just the 330C.

The 330B was wildly popular and HK rebadged some 330A's as 330B's... which leads to a lot of confusion. There are also a good number of factory variants on the which-board-in-which-model category.

• Interesting note about the 330A, 330B B-1, 330B B-2, and later-run 330B.

The 330C, the end of what I'm calling the "minimalist" era, is kind of a bridge to the follow-on Twin Powered era. It is more like a single-power-supply HK 430, but I've lumped the 330C in this grouping or era to keep search and model confusion to a minimum.

There are two models of "330", the 330i and the 330vi, which came much, much later and have nothing to do with the 330A, 330B or 330C... so the 330i and 330vi are not covered here.

Initial waves of models:

• Harman Kardon 230A
• Harman Kardon 330 (no letter)

Second wave of models:

• Harman Kardon 330A
• Harman Kardon 330B (also known as "B-1 series")
• Harman Kardon 330B B-2 series (re-badged 330A)

Final wave:

• Harman Kardon 330C

There are also a number of 330AB models re-badged by other brands:

• Rotel RX-400
• Rotel RX-400A
• Soundcraftsmen 2000A
• Soundcraftsmen 3000A

Other Harman Kardon solid state receiver guides:

• Stratophonic (SR-300, SR-300B, SR-400, SR-400B, SR-600, SR-600B, SR-900, SR-900B)
• Nocturne (Seven Twenty 720, Two Ten 210, Two Hundred 200, Five Twenty 520, Five Thirty 530, Two Thirty 230, Three Thirty 330, Eight Twenty 820)
• 330 minimalist (330, 330A, 330B, 330C)
• Twin Powered (430, 530, 630, 730, 930)

 

[dlucy]

Harman Kardon 230A

• Identical to the Harman Kardon 230 (Nocturne era) other than cosmetics
• In the “minimalist” mostly-silver with black edges case like the 330A and 330B
• Has separate AM and FM tuning panels (but they share the tuning knob)
• Does NOT have pre-out / main-in jacks
• From https://stereonomono.blogspot.com/2015/05/harman-kardon-230a.html :
  • The Harman-Kardon engineering team has completed a high performance stereo receiver which exceeds every specification ever established for medium priced stereo components. The new Model 230A combines the finest stereophonic sound with the industry's most distinctive styling to give high fidelity a new standard of excellence and performance at a price of less than $160.00.
  • Tuber sensitivity of the 230A is extraordinary. It pulls in distant stations without noise or fading. AM and FM performance neve deteriorates with age because the receiver produces no heat to change the value of component parts.
  • And when you tune the 230A to a station, it locks into place and never drifts.
  • The 230A adheres to the same philosophy of design that makes all Harman-Kardon receivers sound more transparent and lifelike. Frequency response, which is usually limited to the narrow range of 20-20,000 Hz in most receivers, is extended well beyond those parameters to give the sound you hear greater clarity and definition. All of the subtle nuances and shadings of music emerge with exciting realism.
• Published specs
  • Power Output: 17 watts into 8 Ω, 20 watts into 4 Ω
  • Total Harmonic Distortion: less than 1%
  • Frequency Response : 20 Hz to 20,000 Hz
  • Power Bandwidth: 15 Hz to 70,000 Hz (at less than 0.3% THD into 8 Ω, both channels driven simultaneously at 8.5 watts per channel)
  • Frequency Bandwidth: 7 Hz to beyond 130 kHz
  • Frequency Response: 15 Hz to 70,000 Hz ±1.5 dB
  • Power Supply: AC, 110 - 240 Volt
  • Dimensions: 390 x 100 x 190 mm (15.4" x 3.9" x 7.5")
  • Weight: 6,5 (14 lbs 15,1 oz)
• Features
  • From HK literature:
    • No deterioration with age because there's no damaging heat. You can expect the same high quality performance from 230A even after years of extensive use.
    • A special electronic circuit automatically switches FM tuner to stereo, the moment a stereo broadcasts received. Special light indicates FM stereo reception. Receiver switches to standard FM automatically when stereo broadcast ends.
    • High speaker damping controls excessive speaker excursions to avoid distortion during sharp bursts of sound. This results in clean, tight bass.
    • Contour for low-volume listening maintains full bass response even at levels where bass normally falls off.
    • Precise D'Arsonval movement tuning mater shows when you have tuned to strongest and clearest signal on AM and FM
    • Stereo in two rooms. Simple front panel switching eliminates the complexity and expense of external switching devices. Headphone receptacle permits personal listening.
    • Newly designed dial illumination shows AM or FM dial scale independently for maximum visibility.
    • Entire top section of receiver turns black when receiver is switched to phono mode of operation.
    • Illuminated push-button ON/OFF switch glows in red to indicate that receiver is on.
    • Continuously variable balance control lets you adjust stereo balance to suit acoustic requirements of your room. Permits you to sit far to one side of your room and still maintain perfect stereo.
    • Tape Monitor Switch for instant comparison of recorded material and original program.
    • Extended frequency response beyond the normal hearing range gives extra realism to the sounds you can hear. 230A sound is cleaner, more transparent, more sharply defined. You can actually feel the difference.
    • Separate illuminated power On/Off switch permits you to turn receiver on and off without upsetting other controls.
    • Heavy, counterweighted flywheel makes tuning smooth as silk
    • Two year warranty on parts and labor.
  • Variants
    • The earlier-era Nocturne 230 is identical except for the cosmetic changes from Nocturne to “silver-faced minimalist”
    • There is something called a 230E that is likely a variant or second sub-model

Useful links and more information:

• AK'er @jpreza shared some great photos of his HK 230A https://www.audiokarma.org/forums/i...330b-b-2-and-330c.960045/page-2#post-15902740
• Harman Kardon 230A / Two Thirty - Faceplate Removal? by @cakeman
• AK'er @Mumbles added some
  • great measurements https://audiokarma.org/forums/index.php?threads/harman-kardon-230a-depth.1082089/#post-17687872
  • and photos of the AM antenna / back of the HK 230A https://audiokarma.org/forums/index.php?threads/harman-kardon-230a-depth.1082089/#post-17688533
• Harman Kardon HK 230A stereo receiver owner's manual
• Harman Kardon HK 230 stereo receiver service manual

 

[dlucy]

Harman Kardon 330 (no letter)

• In the “minimalist” mostly-silver with black edges case like the 330A and 330B
• Has split tone controls (each treble and bass knob can control each channel)
• Capacitor coupled output

The preamp and power amp circuit design of the 330 (numeric digits and no trailing letter) is repeated from the Three Thirty Nocturne. They are a quasi-complementary, cap-coupled design. The output transistors are driven by a single stage of drivers. The Three Thirty and the 330 preamp + power amp circuits are very close copies of each other.

 

[dlucy]

Harman Kardon 330A

• In the “minimalist” mostly-silver with black edges case
• Some have split tone controls (each treble and bass knob can control each channel)
• The Harman Kardon 330A was produced by Roland
• Power output: 15 watts per channel into 8 ohms
• Capacitor coupled output

After late 1973 or early 1974 when Consumer Reports gave the 330B a very favorable rating, H/K asked Roland to produce a batch upgraded 330As and label them as 330B, so one could say that the Roland-produced 330B B-2 series are also 330A, but in a modified or upgraded form. There is a service note covering this changes and some of the actual circuitry and component changes.

Internals:

• The preamp and power amp circuit design of the 330A is repeated from the Three Thirty Nocturne. It's a quasi-complementary, cap-coupled design and the output transistors are driven by a single stage of drivers. The Three Thirty and the 330A/300B preamp + power amp circuits are very close copies of each other.
• The 330A has pre-out and main-in rear panel jacks, so these must be jumped externally for the rest of the unit to feed the internal power amp. You can also use this feature to isolate the preamp or the power amp sections.
• The 330A uses plastic TO-220 devices for output transistors and they are mounted inside the chassis on a multi-piece heatsink. That heatsink is then physically interfaced with the metal rear panel and the metal chassis which all the unit’s boards mount to.
• The 330A has one set of varistors mounted to the internal heatsink.
• The main power supply in the 330A produces 51 VDC from a double-diode rectifier.

The correct service manual for the 330A looks like this:
(important note: some 330A boards have an error on the schematic. see links below for correction)



Adjusting the power amp board on the 330A is covered in the service manual:







Useful links:

• Harman Kardon 330A recapping
• Error on board schematic for some HK 330A units by @painttoad
• Screws, lamps, hardware and other non-electronics bits of a Harman Kardon 330A
• 3D printed replacement speaker terminals for HK 330/a/b

 

[dlucy]

Harman Kardon 330B (also known as "B-1 series")

• In the “minimalist” mostly-silver with black edges case
• There are several variants of the 330B, so be sure to identify which one you have before applying these notes (on the B-1 series) to your 330B.
• There are several internal board and component variants within the B-1 series variant.
• The first generation of the 330B was produced by Shin Shirasuna.
• Power output: 20 watts per channel into 8 ohms
• Capacitor coupled output
• The 330B was a hugely popular receiver and there are a number of variants over multiple long production runs. These won’t make much difference when using a 330B, but they will make a difference if you go to repair, recap or restore one.
• There are several internal board and component variants within the B-1 series variant.
• The first generation of the 330B was produced by Shin Shirasuna. These are known as the 330B B-1 series. This is the first product Shin Shirasuna built for HK.
• In late 1973 or early 1974 Consumer Reports gave the 330B a very favorable rating” and the 330B was suddenly in great demand and Shin Shirasuna could not produce the model fast enough for H/K's dealer orders, so H/K asked Roland to produce a batch of 330Bs (that were basically upgraded 330As) to fill the production shortage. These are known as 330B B-2 series.
• The Roland 330B B-2 series were limited and Shin Shirasuna continued to produce the 330B model for a few more years.
• Later runs of the 330B B-1 series featured ceramic strips in the FM tuner
• Quasi-complementary 2SC1061 Silicon NPN TO-220 (plastic) output transistor

Useful links:

• Harman Kardon HK 330B B-1 series service manual (on Google Drive)
• Recap and restore Harman Kardon HK 330B (recap BOM under development)
• Harman Kardon HK 330B recap, restore and upgrade BOM part list (kinda)
• Which do I have HK 330B B-1 series or B-2 series (visual guide)
• Harman Kardon 330B series B-1 variant #3 recap and restore BOM parts list
• Issues to watch out for... Harman Kardon HK330B or 330B or others
• FM IC chip in 330B B-1 and many others
• 3D printed replacement speaker terminals for HK 330/a/b

 

[dlucy]

Harman Kardon 330B B-2 series (re-badged 330A)




Due to the popularity of the Shin-Shirasuna-produced 330B, H/K asked Roland to produce a batch of 330Bs (that were basically upgraded 330As) to fill the production shortage. These are known as 330B B-2 series.

• In the “minimalist” mostly-silver with black edges case
• There are several variants of the 330B, so be sure to identify which one you have before applying these notes (on the B-2 series) to your 330B.
• Capacitor coupled output
• The 330B was a hugely popular receiver and there are a number of variants over multiple long production runs. These won’t make much difference when using a 330B, but they will make a difference if you go to repair, recap or restore one.
• The 330B B-2 series is, fundamentally, a 330A with a few upgrades and re-branded as a 330B.
• The first generation of the 330B was produced by Shin Shirasuna. These are known as the 330B B-1 series. This is the first product Shin Shirasuna built for HK.
• In late 1973 or early 1974 Consumer Reports gave the 330B a very favorable rating” and the 330B was suddenly in great demand and Shin Shirasuna could not produce the model fast enough for H/K's dealer orders, so H/K asked Roland to produce a batch of 330Bs (that were basically upgraded 330As) to fill the production shortage. These are known as 330B B-2 series.
• The Roland 330B B-2 series were limited and Shin Shirasuna continued to produce the 330B model for a few more years.
• 20 watts per channel into 8 ohms
• Quasi-complementary Silicon NPN TO-220 (plastic) output transistor

Useful links:

• Harman Kardon HK 330B B-2 series service manual (also for HK 330A) (Google Drive)
• Which do I have HK 330B B-1 series or B-2 series (visual guide)
• Simple, short list of transistor replacements for HK 330B B-2 series
• Issues to watch out for... Harman Kardon HK330B or 330B or others
• 3D printed replacement speaker terminals for HK 330/a/b

 

[dlucy]

Harman Kardon 330C

• The second product produced for HK by Shin Shirasuna
• In the “minimalist” mostly-silver with black edges case
• Direct-coupled (neutral sounding) instead of capacitor-coupled (sweet or warm sounding) output
• 23 watts per channel RMS ?
• Has a Slow Start circuit(s) to reduce the "thump" at power on
• Does not have pre-out and main-in jacks
• The Harman Kardon 430 is fundamentally identical to the 330C… except the former has a twin power supply.

Useful links:

• Undocumented “slow start” circuit that protects speakers from the “thump” at power-on. by @xrayspex77
• What function does transistor Q601 perform in the HK 330c power supply by @sregor
• Recapping and restoring a Harman Kardon 330C by @dlucy
• Another Harman Kardon HK 330C restoration and recap by @dlucy
• H/K 330C Restoration by @4thDrWhoFan
• The FM IC chip in the 330C and many others
• Harman/Kardon 330C - speaker terminal replacement or upgrade by @davstev
• The voltage chart in the HK330c service manual and how to use it to narrow where problems are occurring
• Owner's manual for Harman Kardon 330C direct from HK website
• Simple cleaning and repair for FM signal strength meter on HK 330c
• Another simple repair for stuck meter needle on HK330c
• One method for removing the faceplate to access and replace the tuning meter lamps in HK330c
• How to remove the power lamp in the HK 330c

 

[dlucy]

Rotel RX-400

• Like the Harman Kardon Three Thirty
• Pre-driver/driver adjustment same as 330A as noted here
• May be related to the Sears 570.7410 stereo receiver as noted here

Useful links and additional infomation:

• AK'er @peterp1 shared great photos of his Rotel RX-400 here: https://www.audiokarma.org/forums/i...330b-b-2-and-330c.960045/page-2#post-15902778

 

[dlucy]

Rotel RX-400A stereo receiver




Like the Harman Kardon 330A

Useful links:

• Rotel RX-400A Fix up and clean up by @Eastham
• Rotel RX-400A - a rebranded Harman Kardon 330A or 330B

 

[dlucy]

Soundcraftsmen 2000A

 

[dlucy]

Soundcraftsmen 3000A

As far as I can tell, the SC-3000A is a relabeled HK 330B, but I have not confirmed this yet by schematic or looking inside one.

There is also a Soundcraftsmen SC-3000 (no letter "A") which is similar, but not the same.





Specifications (from HiFiEngine):

• Tuning range: FM, MW
• Power output: 30 watts per channel into 8Ω (stereo)
• Frequency response: 9Hz to 100kHz
• Total harmonic distortion: 0.2%
• Damping factor: 35
• Input sensitivity: 2.5mV (MM), 160mV (ceramic), 130mV (line)
• Signal to noise ratio: 67dB (MM), 80dB (line)
• Speaker load impedance: 4Ω to 16Ω
• Dimensions: 17-11/12 x 5 x 12-1/2 inches
• Weight: 8.9kg

Useful links:

• Owner's manual and flyer for Soundcraftsmen 3000A at HiFiEngine.com
• Photos of insides of Soundcraftsmen 3000A

 

[Hoewieloewie]

Hello. Thanks for all the information. Nice to know the differences between 330, 330A, 330B (B-1 and B-2 series) and 330C. Last saturday, I picked up a 330B (B-2 series I found out with your information). I like it very much, great performance, good sound, nice looking.

My 330B (B-2 series):
https://audiokarma.org/forums/index.php?threads/harman-kardon-330b-receiver-easy-fix.970436/

 

[Hoewieloewie]

Hello. I have a question about the stereo lamp of my 330B B-2 series, if it's alright to post it here of course. I found the right service manual and in this manual, I see that the stereo light is as follows: 60 volt, 30 mA. To me that seems unlikely and I think it's not right. What is your thought about this?

 

[KentTeffeteller]

Note also, 330 is a USA made receiver. Japanese production began with the 330A.

 

[dlucy]

Hello. I have a question about the stereo lamp of my 330B B-2 series, if it's alright to post it here of course. I found the right service manual and in this manual, I see that the stereo light is as follows: 60 volt, 30 mA. To me that seems unlikely and I think it's not right. What is your thought about this?

They must mean 6.0V, not 60V. I use 8V lamps for these.

 

[Hoewieloewie]

Hello. Thanks, I think that makes more sense.

 

[dlucy]

Note also, 330 is a USA made receiver. Japanese production began with the 330A.

Good fact. I'll add it above.

 

[davstev]

Great thread, super interesting and informative. Thanks Doug, for your considerable efforts. Yesterday I picked up a nice 330B in great cosmetic shape and is sonically great. Unfortunately, it has a transformer hum. Not terrible, but still bothersome. When I put my hand on the case, it reduces the hum by half or so.

Anyway, I'll need to try to get to the bottom of that. I suppose that I will start by seeing if it's not so much a case of the breakdown of the laminate structure of the tranformer, but, something faulty in the power supply putting strain on the transformer. Are all power transformers within the variants of the 330B series interchangeable? I've seen some that are all black whereas mine is black with brass coloured caps.

 

[dlucy]

Are all power transformers within the variants of the 330B series interchangeable? I've seen some that are all black whereas mine is black with brass coloured caps.

Not really. They all have a ~6VAC secondary for the bulbs and a 45 to 50 vac secondary at 2-3 amp for everything else, but the 330A is low (45v or so) compared to the 330b B1 and B2 (50v or so).

you could swap them, sure, but you may have fewer volts output from the big secondary than you want.

 

[davstev]

Thanks for the great info. Is there any way to easily identify if this is of the 45 or 50 VAC variety?