{"id":9189,"date":"2010-04-27T16:54:05","date_gmt":"2010-04-27T14:54:05","guid":{"rendered":"http:\/\/www.hifi-advice.com\/blog\/?page_id=9189"},"modified":"2020-07-22T08:45:24","modified_gmt":"2020-07-22T06:45:24","slug":"jrdg-company-special-model-9","status":"publish","type":"page","link":"https:\/\/www.hifi-advice.com\/blog\/jrdg-company-special-model-9\/","title":{"rendered":"JRDG Company Special – Model 9"},"content":{"rendered":"

<\/b>The Model 9 was available in a few different versions:<\/p>\n

Model 9 (1992-approx 1998)<\/strong>
\nModel 9T (1998-approx 2000)<\/strong>
\nModel 9Ti (approx 2000-approx 2002)<\/strong>
\nModel 9Ti HC (approx 2000-approx 2002)<\/strong><\/p>\n

Some of the above models were available in AC only or BPS<\/a>\u00a0versions. In case of the latter, the BPS unit would replace the AC powersupply unit, rather than complement it as with all other Rowland amps.<\/p>\n

Retail price of the Model 9T in 1998\u00a0in the Netherlands 40.749\u00a0euro (89.800 guilders) per set<\/p>\n

\"rowland-model-9-bakken-met-voeding_550pix\"<\/p>\n

Reference poweramps and natural partners at the time for the Coherence II consisting of two huge boxes per channel. There were a few versions, one important difference being that the 9 could be ordered as an AC or DC version, meaning normal AC operation or power via a BPS (Battery Power Supply). Per channel, one box is the amp itself, the other is either the combination of BPS and switched power supply or only the massive transformers of a linear power supply. These big boxes deliver ample power but perhaps not as much as one might think judged by their imposing looks: 350 watts per channel. This seems lowish compared to big Brystons but Rowland watts are much like tube watts: there’s always much more power than you’d think! The original 9’s are super-stable and can drive virtually any loudspeaker. They draw a lot of current from the wall outlet though: 500 watts idle (switched on but not playing music) and 1200 watts maximum. That’s per channel!<\/p>\n

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Even though these amps reportedly sounded amazing; both delicate and refined as well as powerful and colourful, there seemed to be a problem with (a part of) the 9ti switched power supply. This supply has some parts in common with the model 10 that I owned and besides my own model 10’s power supply problems, I’ve heard of and read about a few other occasions where (part of) the switched power supply broke down. I think there may have been a reliability issue in a batch of parts of the power supply but this is not confirmed. Nevertheless, sonically\u00a0these amps are supposed to be amongst the very best available.<\/p>\n

A long time user recently reported that his model 9ti HC’s have been working utterly reliably. He has never had a problem. So much as is the case with the Model 10’s, there are some samples that are problematic but when your sample is working just fine it need never break down.<\/p>\n

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\"jeff-rowland-model-9-synergy_550pix\"<\/p>\n

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Above: sticking the 9’s in an enclosure with a very narrow opening is not a good idea…<\/p>\n

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Original Model 9 Inside Pictures<\/h2>\n

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The original Model 9 reminds me of a beefed-up version of the Model 6 that I own: same bipolar transistors, same circuit board material, same manner of capacitor-clamping and same line stage modules. I have never heard a model 9 but I assume that these initial models could potentially be regarded as more powerful model sixes.<\/p>\n

Model 9T Inside Pictures<\/h2>\n

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\"rowland-model9t_550pix\"<\/p>\n

The Model 9T is a more modern version of the Model 9 above, with several circuit changes. I have no official information regarding the exact differences, or as to what’s inside those tubes… \u00a0but considering that the Model 6 has two toroidal power transformers inside similar tubes, it is likely the same for the Model 9. Unlike the original Model 9’s similarity to the Model 6, the T version strikes me rather as a variation on the model 10 with its orange buss bars and integrated IC’s instead of bipolar transistors, it does seem like it (the AC version at least) doesn’t use the switched power supply though and that’s a good thing because linear power supplies are super-reliable.<\/p>\n

Model 9Ti Inside Pictures<\/h2>\n

The Model 9Ti is a refinement of the Model 9T. Alas, I have no pictures or information on what constitutes the exact changes, but I guess that they must be in the power supply only and this could be the moment when the linear power supply changed into a switching power supply.<\/p>\n

I’m leaving this section in, hoping that one day I will find more info or even better, pictures of the Model 9Ti’s power supply.<\/p>\n

If you have any more information,\u00a0do please let me know<\/a>.<\/p>\n

Model 9Ti HC Inside Pictures<\/h2>\n

\"rowland-model-9tihc-dsc_1692_550pix\"<\/p>\n

The Model 9Ti is identical to the Model 9Ti above but with double the amount of power IC’s\u00a0allowing double power output. Alas, this also means double power consumption: 1000 watts per channel idle and I don’t know for a fact they take in at maximum power but it could well be around 2000 watts each.<\/p>\n

\"rowland-model-9tihc-dsc_1692_closeup_550pix\"<\/p>\n

Above is a closeup of one of the Model 9Ti HC’s power circuit boards. You can see that there are no regular bipolar transistors anymore, but multi-leg IC’s instead.<\/p>\n

External Power Supply or BPS unit DC Cable Compatibility<\/strong><\/p>\n

The model 9 amps used a two pin Fischer connector, male and female on each end with ground carried in the shield and shell. Sometimes the original rubber jacket would degrade and while not affecting the functionality of the cable, a new cable sheath, like heatsink tubing, could be installed over the degraded rubber. In these cases, the Cardas branding would be covered.<\/div>\n
<\/div>\n
The model 2,6 and 8 amps used an Amphenol brand connector of 8 pins to use when connecting BPS battery supplies. These also are all the same within their group and made by Cardas to JRDG spec.<\/div>\n

Model 9 Features<\/h2>\n

Two parallel connected XLR Balanced Input jacks for balanced (Differential Mode\u2122) system configurations<\/p>\n

Two parallel connected RCA Input jacks for unbalanced (single-ended) system configurations<\/p>\n

Two parallel connected speaker output connectors<\/p>\n

User-selectable overall gain of 26 or 32 dB<\/p>\n

User-selectable input impedance of 36k or 600 ohms for both balanced and unbalanced inputs.<\/p>\n

User-selectable absolute phase on balanced input<\/p>\n

User-selectable input muting<\/p>\n

User-selectable switching between balanced and unbalanced inputs<\/p>\n

Front panel standby\/power button illumination can be turned off during listening<\/p>\n

Optional remote (wired or wireless) power ON\/OFF switching<\/p>\n

Automatic temperature stabilizing circuitry maintains constant operating temperature<\/p>\n

Standby power condition reduces warm-up time<\/p>\n

Fail-safe operation provided by user-resetable AC and DC magnetic circuit breakers located on rear panel<\/p>\n

Quiet, transient-free operation during power and function mode switching<\/p>\n

Automatic input muting under anomalous input or output operating conditions<\/p>\n

Balanced Differential Mode\u2122 circuit topology implemented from input to output<\/p>\n

Plug-in modules, containing critical electronic circuitry, enhance thermal stability, mechanical integrity and serviceability<\/p>\n

Low-resonance, structurally integrated chassis of precision machined aluminum alloy components<\/p>\n

Model 9Ti Technical Specifications<\/h2>\n

The specs below refer to the latest iteration of the product, not HC version<\/strong><\/p>\n

OUTPUT POWER CONTINUOUS RMS WATTS<\/strong>
\n@ 8 OHMS 350 WATTS
\n@ 4 OHMS 700 WATTS<\/p>\n

BANDWIDTH<\/strong>
\n0.1 Hz to 160 kHz, -3 dB<\/p>\n

SLEW RATE<\/strong>
\n30 volts per microsecond<\/p>\n

THD AND NOISE<\/strong>
\nless than 0.06% at rated power<\/p>\n

DAMPING FACTOR<\/strong>
\ngreater than 300, 20 Hz to 20 kHz, 8 ohms<\/p>\n

OUTPUT CURRENT<\/strong>
\n70 amps continuous, 140 amps peak<\/p>\n

OVERALL GAIN & SENSITIVITY (1 WATT, 8 OHMS)<\/strong>
\nuser selectable on back panel
\n26 dB or 32 dB; 141 mV or 71 mV<\/p>\n

INPUT IMPEDANCE<\/strong>
\nBALANCED 36k or 600 ohms
\nUNBALANCED 36k or 600 ohms
\nuser selectable on back panel<\/p>\n

COMMON MODE REJECTION RATIO<\/strong>
\ngreater than 60 dB, 20 Hz to 20 kHz<\/p>\n

ABSOLUTE PHASE<\/strong>
\nuser selectable on back panel
\nnormal or phase-inverted<\/p>\n

INPUT MUTE<\/strong>
\nuser selectable on back panel<\/p>\n

POWER CONSUMPTION (PER CHANNEL)<\/strong>
\n50 watts standby; 500 watts operating, idle;
\n1200 watts maximum<\/p>\n

INPUTS<\/strong>
\nBALANCED\/UNBALANCED
\nuser selectable on back panel
\n2 per channel (XLR)
\n2 per channel (RCA)<\/p>\n

OUTPUTS<\/strong>
\n2 pair binding posts per channel<\/p>\n

DIMENSIONS<\/strong><\/p>\n

POWER SUPPLY<\/strong>
\n17.5 in (W) x 22.0 in (D) x 11.4 in (H)
\n44.5 cm (W) x 56.0 cm (D) x 28.5 cm (H)<\/p>\n

AMPLIFIER<\/strong>
\n17.5 in (W) x 22.0 in (D) x 11.4 in (H)
\n44.5 cm (W) x 56.0 cm (D) x 28.5 cm (H)<\/p>\n

WEIGHT (PER CHANNEL)<\/strong>
\nPOWER SUPPLY 128 lbs. (58 Kg)
\nAMPLIFIER 92 lbs. (42 Kg)<\/p>\n

BPS (Battery Power Supplies)<\/h2>\n

BPS-9<\/a>
\nBPS Main Page<\/a><\/p>\n

More Jeff Rowland<\/h2>\n

Jeff Rowland Company Special Main Page
\n<\/a>Jeff Rowland Company Special Power Amplifiers<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

The Model 9 was available in a few different versions: Model 9 (1992-approx 1998) Model 9T (1998-approx 2000) Model 9Ti (approx 2000-approx 2002) Model 9Ti HC (approx 2000-approx 2002) Some of the above models were available in AC only or BPS\u00a0versions. In case of the latter, the BPS unit would replace the AC powersupply unit, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-9189","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/pages\/9189","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/comments?post=9189"}],"version-history":[{"count":12,"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/pages\/9189\/revisions"}],"predecessor-version":[{"id":24558,"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/pages\/9189\/revisions\/24558"}],"wp:attachment":[{"href":"https:\/\/www.hifi-advice.com\/blog\/wp-json\/wp\/v2\/media?parent=9189"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}