Rotel RX-400A - a rebranded Harman Kardon 330A or 330B
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Yep, actually the other way 'round. Roland Electronics (Rotel) made them for H/K. They made the whole line including the quads, you can find them under both brand names with their proprietary faceplates but identical circuit boards inside.
I've got one of those RX-400a receivers, identical to the HK except they went with a different heat sink on my example plus it has a universal power supply.
I've got one of those RX-400a receivers, identical to the HK except they went with a different heat sink on my example plus it has a universal power supply.
I'm not sure that I understand what you're saying. Are you saying Rotel designed the circuitry/layout/chassis for the Three Thirty, 330A, and 330B and Harman Kardon just licensed those designs and rebranded them as HK? If that is indeed what you're saying, do you have a source for that info?
I appreciate the pointers and have already used Google and TheVintageKnob, finding nothing on Rotel or Roland and Harman Kardon. Maybe I'm searching for the wrong thing. Where are you all finding this info on HK and Rotel history?
As I understand it Roland Electronics (Rotel) in Japan was already building receivers of their own as well as units for other companies to rebrand when H/K stopped building their own equipment in Plainveiw NY. HK had the Rotel units built to their specs but apparently that consisted mostly of cosmetic and hardware changes as the circuits are primarily the same. American companies outsourcing products from Japanese manufacturers who were already manufacturing their own line was a fairly common practice. You could find Japanese built Fisher receivers with identical twins under the Hitachi and later the Sanyo brand, but they were Hitachi and Sanyo units that were rebranded as Fisher for the US.
Probably the last of US built HK electronics were the "Stratophonic" phono systems from 1968 at the end of the germanium era:
Which you could also get with a Nak built open reel deck BTW:
Some threads about the Rotel / HK / Procom receivers:
http://audiokarma.org/forums/index.php?threads/hk-330a-rotel-400a-separated-at-birth.674943/
http://audiokarma.org/forums/index.php?posts/9935690/
http://audiokarma.org/forums/index.php?posts/7276485/
The threads and their nudies definitely show the units are similar or practically identical. Good info.
Do you have a source for the Rotel / Harman Kardon history? I'm looking and finding nothing that tells me who designed what.
No official source, just what I've heard from others who have made the same observation and the fact that Fisher and Scott did the same thing. Sometimes I wonder if HK worked with Roland on the design for the first Japanese made Nocturne series and struck some kind of a deal allowing Roland / Rotel to liscence out the circuitry but I can't seem to find any official word on that. Details seem hard to come by but Rotel was definitely making them under different brands (including H/K) at the same time.
I'm really interested now in learning whether the ThreeThirty/330 design was Roland or HK's Matti Otala. This post has someone who appears to be a HK tech, so maybe they can help. http://audiokarma.org/forums/index.php?threads/harman-kardon-330-variations.396817/#post-5110206
Well that's the best and most trustworthy information I've ever read on the subject of the 330 variants, very interesting stuff - thanks Doug! I didn't know Shin had anything to do with the early 330 models, and very interesting about the different RF circuits too.
Thanks to you, too, as I thought it was the other way around until you pointed it out.
The 330A/B variants that I've documented here are usually the power-supply/multi-voltage/FM-pre-emphasis differences and FM-tuner/MPX differences. There is definitely one unit in the 330B stack that has the later-design, nicer ceramic-filter version of the FM tuner circuit*. I always thought it was HK doing different production runs and different manufacturers. I would _really_ like to know the more-detailed history on these.
* One of the guys on the FM tuner info site / mailing list has a nifty FM circuit add on on to improve DX or separation but it only works on the units with the three-legged ceramic filters.
I would really like to know more about them as well. I could be wrong but I don't think Matti Otala was involved in the 330 design as he was with H/K from 1978 to 1980 (hence the emphasis on TIM distortion specs in the later H/K literature).
Good to know there are tweaks for these receivers. Truthfully I have always found the FM sections on them to be pretty decent, but then again I use a rotating chimney antenna in an area with great selection so I'm kind of spoiled!
BTW I just remembered another one of the differences between my Rotel RX-400a and the HK 330b is the addition of a "Dyna-Quad" type of speaker phasing switch in back of the Rotel used to simulate 4 channel sound when using speaker A + B (I believe the holes are in the chassis of the H/K but the switch isn't there).
Good to know there are tweaks for these receivers. Truthfully I have always found the FM sections on them to be pretty decent, but then again I use a rotating chimney antenna in an area with great selection so I'm kind of spoiled!
BTW I just remembered another one of the differences between my Rotel RX-400a and the HK 330b is the addition of a "Dyna-Quad" type of speaker phasing switch in back of the Rotel used to simulate 4 channel sound when using speaker A + B (I believe the holes are in the chassis of the H/K but the switch isn't there).
In a thread on Facebook today, a person has set the record straight on the whole HK-Rotel-Roland thing. Here's the pertinent parts of his post:
I worked at the Plainview offices as part of the New York Audio Team and knew the engineers directly. My tenure was from 1974 to 1976. Burt Brooks came over from Dual (of turntable fame), and ran the NYAT Sales group before he became the Nat'l Sales Manager for HK. (Some day, if asked, I'll let you know how Dual got its name.)
Roland (what people now call Rotel in terms of a HiFi company) only constructed under contract. HK in the US designed them all, every last one. Roland constructed the 330A, the 330B, the 630, and the 930. I am not sure who constructed the original 330
The 330c was constructed by Silver (Shin-Sirasuna of Japan), not Roland. That was also the case for the 430 and the 730.
We had Crown Radio of Japan assemble our old quadraphonic receivers (50+, 75+, 100+, 150+, 800+, & 900+). We were going to build the 700+ in Plainview, but when Quad died, it was reconfigured as the stereo TA-600 (Tuner Amplifier), and built in the US.
The first HK cassette decks (CAD4 & CAD5) were built by Nakamichi for us (Fisher also had Nakamichi build their first decks (RC60 & RC80). So did Advent (the second is the one everyone remembers; it used a transport mechanism that was sourced from Wollensak aka 3M).
Starting with the HK1000, Silver manufactured them for us as we dropped Nakamichi due to transport quality issues. The HK1000 and the HK2000 had constant current drive to the record heads, just like the professional Studers that were in all of the recording studios, and the only consumer decks to do so..
The Citation 11, 12, 13,14, 15, and 16 products were all assembled in the Plainview facility during my tenure. (Note, I have the Engineering sample set of Citation 13 speakers to this day.)
During my tenure there, we released the Citation 16 Power Amp (designed by Bernie Gaines), the HK2000 cassette deck, the Rabco ST-7 Linear Tracking turntable, the 330c and the 430.
Dick Shahinian (of Rectilinear and Shahinian Acoustics fame) designed the Citation 13 loudspeaker. 500 pair were built.
I also had the honor of meeting, and working with, Leon Kuby for about 6 months. He was the ears behind the Citation 11 and 12 and 14/15 models, as well as the Citation 16a. Bert White (of Audio magazine fame) and others referred to Leon as the Audiophile's audiophile. When I met Leon, he did not own any records as he and Bert White had moved on to Studio tapes from the major studios. Yes, 1" Dolby A tapes. Simply amazing.
Doug, I really worked there.
-Stan Skatvedt
Roland (what people now call Rotel in terms of a HiFi company) only constructed under contract. HK in the US designed them all, every last one. Roland constructed the 330A, the 330B, the 630, and the 930. I am not sure who constructed the original 330
The 330c was constructed by Silver (Shin-Sirasuna of Japan), not Roland. That was also the case for the 430 and the 730.
We had Crown Radio of Japan assemble our old quadraphonic receivers (50+, 75+, 100+, 150+, 800+, & 900+). We were going to build the 700+ in Plainview, but when Quad died, it was reconfigured as the stereo TA-600 (Tuner Amplifier), and built in the US.
The first HK cassette decks (CAD4 & CAD5) were built by Nakamichi for us (Fisher also had Nakamichi build their first decks (RC60 & RC80). So did Advent (the second is the one everyone remembers; it used a transport mechanism that was sourced from Wollensak aka 3M).
Starting with the HK1000, Silver manufactured them for us as we dropped Nakamichi due to transport quality issues. The HK1000 and the HK2000 had constant current drive to the record heads, just like the professional Studers that were in all of the recording studios, and the only consumer decks to do so..
The Citation 11, 12, 13,14, 15, and 16 products were all assembled in the Plainview facility during my tenure. (Note, I have the Engineering sample set of Citation 13 speakers to this day.)
During my tenure there, we released the Citation 16 Power Amp (designed by Bernie Gaines), the HK2000 cassette deck, the Rabco ST-7 Linear Tracking turntable, the 330c and the 430.
Dick Shahinian (of Rectilinear and Shahinian Acoustics fame) designed the Citation 13 loudspeaker. 500 pair were built.
I also had the honor of meeting, and working with, Leon Kuby for about 6 months. He was the ears behind the Citation 11 and 12 and 14/15 models, as well as the Citation 16a. Bert White (of Audio magazine fame) and others referred to Leon as the Audiophile's audiophile. When I met Leon, he did not own any records as he and Bert White had moved on to Studio tapes from the major studios. Yes, 1" Dolby A tapes. Simply amazing.
Doug, I really worked there.
-Stan Skatvedt
Mantolaman
NC
A lot of good information in this thread, thanks for posting, to you and all the other contributors.
Just wondering what you found when you 'opened' the 400A? Your opinion of it, build quality, etc.
Here are a few photos comparing the RX-400A to the (proper) 330A. After these, I've added two links to a complete set of photos of the same. Enjoy.
HK 330A
Rotel RX-400A
Lots of photos of the Rotel RX-400A: https://drive.google.com/drive/folders/17N6hHSn3Yy8Ltw6_4mIUNoaDcEX_K8ST?usp=sharing
Lots of phtotos of the Harman Kardon 330A (remember there are plenty of variants, so this one is just one of those): https://drive.google.com/drive/folders/1--aUI_7ds56Em1bruBFZCDxrGD4_PWca?usp=sharing
HK 330A
Rotel RX-400A
Lots of photos of the Rotel RX-400A: https://drive.google.com/drive/folders/17N6hHSn3Yy8Ltw6_4mIUNoaDcEX_K8ST?usp=sharing
Lots of phtotos of the Harman Kardon 330A (remember there are plenty of variants, so this one is just one of those): https://drive.google.com/drive/folders/1--aUI_7ds56Em1bruBFZCDxrGD4_PWca?usp=sharing
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Paulfrazer
New Member
I have just come across this thread whilst researching the Rotel RX400A vs HK 330A. I have had a Rotel RX400A since new and a few years ago it developed a power supply type hum. I got it out earlier this year and replaced the caps in the power supply but that didn't help so in desperation I replaced the 1S1850 rectifier with a couple of UF5403 diodes. This completely cured the hum. There isn't room to place both diodes on the top of the circuit board so I put one on top and the other below. Just an addition to this interesting thread in case anyone has a similar issue.
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