Marantz 2330 Receiver

Marantz 2330

Got this unit in for some power supply issues and did a few specific boards per customer. 

Power Supply

Initially the relay was engaging longer over time about 12 seconds, verified voltages and the H805-807. Turned out to be a leaking cap that tested bad under duress. The relay is on an ball, a 4dpt type. This particular one was pulled and the contacts treated and cleaned. Used here were Panasonic FR's and FC's. Also the 131B diodes were replaced with MUR1620 common cathode diodes. Monitored and regulator adjusted to 35.5VDC, relay sits at about 5 seconds.

Phono

The axial was replaced with a Nichicon TVX and Silmics and WIMAs used for the tantalums. H409 diode was replaced with two 1N4148 in series and heat-shrinked.  H405/406 (2SC1175A) were replaced with matched hfe KSC1845's.

Tone

This board has the nice fat browns and the skinny yucky raw films. The gray films at CE05/06 were replaced with Panasonic ECW PP type. CE37/38 are bipolar lyrics, replaced with MUSE's. The rest are Silmic and WIMA's. Mind 5mm spacing through for lead spacing on the WIMA's

Amplifier

Each boards differential pairs (Q701/702) were replaced with matched KSC1845's with compound and heat-shrinked together, the KSC1845 has the appropriate pinout BCE. The bipolar were replaced with WIMA MKS2's and Silmic used throughout. New thermal compound and MICA insulators installed. 

 The biasing procedure is extremely easy on this unit with the test points mounted specifically to the sides, top mount. There is a service error in the manual, Bias is adjusted at R727 and DC offset is adjusted at R726.

A new eg1018-nd switch and X1Y2 safety capacitor installed, along with both dubbing jacks, both shaft had been broken from the body of the assembly, I added an eyelet to the grounding jack of the jack to make the common ground easier to share. 

To be honest I didn't expect much out of this unit, I was already convinced the 2325 is as good as you can go. Turns out I was wrong, the 2330 has that nice Marantz depth to the soundstage yet this modern…clear overtone I haven't heard in other models.

Marantz 1070 Integrated Amplifier

Marantz 1070

Heres a real early commission of a Marantz 1070 integrated, a neat design on a model you seldom come across.

P800

Silmic II's and a FG were used on the power supply from a recommendation on this particular unit,H801 was a common cathode MUR1620 diode, where a 131B was. The, Adjustments were made at J810 & J811 adj. R807 to 40VDC initial 41.00V Reset to 40.00V. As much of the glue and so fourth cleaned off nicely.

A new EG1018-ND switch was placed with the safety cap across.

PE01

I used my typical assortment here, Nichicon muse for the bipolar's and WIMA's in place of the tantalums along with Silmics, again I recommend keeping the large brown films, unless a must some ECW PP's there. I think these selections really have some harmony here.

P400

Silmic and WIMA's were again used here with transistors to bother on this model, a slight variations from the 845's with 0.00ma leakage and testing well.

P700

The removal of the amp board can be tricky, but I found if you have the heatsink mounted SVT diodes and unscrew the rear panel you gain an easy access point. Silmic/WIMA and FG's were used along with a special Elna Cerafine, these are very nice, albeit pricey electrolytic. The bias and offset have pretty easy tap locations as well. New thermal compounds and mica were done as well just to freshen up the old stuff.

Idle Current Adj.

J714 & J716 adj. R733 to 10mv initial 10.5mv Reset to 10.00mv

J715 & J717 adj. R734 to 10mv initial 10.00mc Set

DC offset

J723 & J722(G) adj. R711 to 0.mv initial 5.0mv Reset to 0.00mv

R724 & J722(G) adj. R712 to 0.mv initial 3.5mv Reset to 0.00mv

The Main filter caps have a unique location mounted under the chassis on this model, these were replaced with two 10000uf 50V 

647-LKG1H103MESCBK Nichicon KG's. The higher capacitance leads to us to a more refined and deeper lower end.

A blue LED replaced the original yellow incandescent to give that typical  blue Marantz to match the owners Model 150 Tuner. 

N.S.

Marantz 2220B Receiver

Marantz 2220B

This is kind of a touch and place restoration, with selective boards. A nice open model to work on, with a symmetric amp PCB. Was quite blown away by this little model, though Im not really a B variant fan. 

P800 Power supply

I've been really favoring the Panasonic FC's and FR's now in the power supply, their robust, and rated well. H803/H804 the 131B/ 132B diodes were replaced, the 131 with a common cathode MUR1620 and the 132B with two UF4005 common anode.. H808 s1b-01-02 was replaced with a s ingle UF4005. Voltage was adjusted at J811 & J812 @ R808 to 35VDC.

P700 Amp Board

All the lyrics here were replaced with either Silmic II's or FG's. H705/706 MV13 were replaced with two 1N4148 diodes in series and shrinker, and the differential pair of H701-H704 were replaced with matched KSA992's, greased and shrinked.

This unit is literally so pristine I even doubt its seen many hours judging by the switch and relay, so the relay here was only cleaned at the contact, but its a LY-02 Omron type. Set idle per channel at 20.4mV Left and Right with offset at 0.04 L/R and stable as can be. Runs quite cool even at an hour or two.

P500 Tone Board

Lytic's here are Silmics II's, at CE23/24 Nichicon MUSE ES bipolar are used. With WIMA MKS2's used at CE19/20 and CE 21/22.

P400 Phono

Lytics again here were replaced with all Silmic II's, the two tantalums C401/402 were replaced with WIMA MKS2, the BJT's here are fine as is.

New mica and thermal compounds were applied along with a new EG1018-ND dpdt switch with a vishay X1Y2 safety cap.

N.S.

Marantz Model 30 Integrated Amplifier

Marantz Model 30
Grabbed this for my personal use, got lucky a bit; this particularity model having a serial of 1640!  The Power supply, relay and amplifier boards are all very similar to the model 15. 32 and model 33 pre amplifier. Originally these use 2 channel moto outputs, very robust unit at 120W total RMS.

Im really a huge fan of symmetric isolated board topographies, and the assemble is very straightforward with most boards or clamps being fairly easy to access along with test points. the only major draw back was the U shaped chassis, which doesnt allow you to remove the back panel as its a folded chassis.

This unit had suffered a catastrophic cascade failure of the amplifier channel, protect and PS boards. Heres an outline to my method.


The primaries and secondaries are not shorted so we add first the the power supply board to the primaries;

At the power supply pin 1 and 9 were noted to have crisped traces causing intermittent connection, Along with C404/405 venting excessively.
The Diodes CR401-404 are all general purpose 1.5a rectifier diodes. Q401/402 I believe helps regulate CR401-404 diode bridge. The manual states
zeners CR405/406 are the voltage references for the two transistors. All the transistors and diodes were updated and the electrolytics replaced with
quality axials.

CR401/404 1.5a rectifier (512-1N5393) IN5393 equivalent (common)
CR405/406 18V 500mW zener (833-1n5248B-TP) IN967A equivalent (common)
Q401 BJT NPN (512-KSC2690AYS) SPS2219 equivalent
Q402 BJT PNP (512-KSA1220AYS) SOS2220 equivalent
c401/408 500uf 25v
C404/405 100uf 50V
C409-412 680uf 63V

Next lets add the relay rail back to the circuit. Which is when it started to trip my DBT again. On the relay an uber common fail point is the bridge rectifier CR301, which was shorted across the AC/AC and a bridge rectifier is basically 4 one way diodes together so. The relay would also not engage,
 and the manual notes diodes CR302/303 which are also general purpose 1.5a rectifiers control the positive voltage for the relay. They tested okay  but the relay had heavy signs of carbon build up and what looks like arching. along with the shorted bridge would explain why the carbon comps at R307/308/311 were damn near burnt.These three resistors were changed to small 5W wirewounds. Q302 BJT transistor is a common Moto SS47. Q301/303 are both NPN BJT SPS439 transistors.  Q301 I believe is a protection in case a voltage of excessive voltage, which shorts Q303. (excessive draw) The relay K301 can be replace with a standard available omron with the documented coil/contact conversion. thier are three main lytics two change here, one value is kinda tricky to assemble, you will probably have to put two capacitors in series.

K301 OMRON MY-02 24VDC
Q301/303 BJT NPN (512-BC546ABU) SPS439 equivalent
Q302 BJT NPN (MJE182STU) moto SS47 equivalent (common)
CR302/303 1.5a rectifier (512-1N5393) IN5393 equivalent (common)
R307/R308 1.5k 5W
R311 150ohm 5W
C301 33uf 16v
c302 125uf 25V
C303 10uf 100V

C3/4 Filter Caps 6800uf 50V screw type (565-3328-ND)

Okay so now on the DBT I had no shorts with the power and relay boards in, lets add the right board that I presume works. and the DBT confirms at least no shorts. Now we can add and remove the channels
while testing or making final adjustments very easily on this model. by removing the red/blues rails from each channel to the large filters caps C3/C4 capacitors.

Okay I added back the left channel and the dbt indicated a short. Now this channel already had been worked on by a mystery slob, the ouputs had been replaced and the foil side of
the pcb was a damn mess. half the job on this board was repairing broken eyelets and traces. Now afer talking with some people we theorize the only way to achieve as much damage
as this board did was to be overdriven to the extreme, were talking 4 shorted transistors galore.  What ended up being easiest for this board was to pull all of the zener, diodes, transistors and replace the lytics.
Now a guy could slowly add back and fourth confirmed transistors from the right side but thats a good way to fry something else down the line. IMHO if I narrowed it down to the channel...whats a half
hours work pulling components and testing? nothing. 

For starters the input signal comes into the Amp in, theres the Q202/201(MPSA09) differential/inverter stage which Q202 was shorted at (c-e), and then the  inverter output is applied to the  predrivers Q206/208 which are the common BJT MPSA20/70
counter parts both of which were shorted (c-e). this output from Q206(ss48)/208(SS47) is applied to the Q209/210 drivers which in turn power the outputs Q1/Q2 (SJ2046/2047). Q207(MPSA20) was also shorted (c-e). R245/R213 were upgraded to carbon Films
and the lytics at C201/201 were upgraded to FG's, along with a new axial at c209.


Q201/202 MPSA09
Q204 MPSA70
Q205/207 MPSA20
Q203/206 (MJE172STU) moto SS48 equivalent (common)
Q208 (MJE182STU) moto SS47 equivalent (common)
C201/203 10uf 16v
c209 47uf 16v

Q1 MJ21195G(PNP) SJ2047 moto equivalent
Q2 MJ21196G (NPN) SJ2046 moto equivalent

Power switch is a standard EG1018-ND  7a 125V DPDT with a X1Y2 safety cap, though it will take much modification to make it fit proper.

Also added was a new power cord and rear input/output RCA terminals, along with new speaker terminals.  The manual call for use of a Watt meter for the BIAS but using a DMM
across collectors of Q1/Q2 you can adjust R224 pot for Bias, or the across the emitter resistors R230/231 and adjusting R224 pot. The manual does call for a load when doing these adjustments.

N.S.

Marantz 2325 Receiver

Marantz 2325 Receiver
Got this unit in on a commission, the owner had replaced the large lyrics prior to coming onto my bench
So far this has got to be right up there with the 2230 as a favorite unit, clean and easy to work on. Very well built and sounds just amazing, with a modern clarity to it.

P800 Power Supply/Relay
The first thing I noted the lytics had signs of obvious heat exposure present with the shrinking and the large capacitor at C803 had leaked lytic material all over the near by resistors including R816 in the control network. At some point someone had replaced the Omron relay with a MY-2 type, though an LY is standard for the 2325.

All the electrolytic were replaced with high temp Panasonic FC's which seem to do quite well in the Psupply. Relay protection diodes H808/H809 131B  were replaced with like to-220 MUR162 and H810 WZ-140 diode with a 1N5422. The coated resistors were replaced with 5% carbon films at rated value. The relay was replaced with the specified Omron LY-2 24VDC type. All the Glue was soaked with acetone and gently removed. The regulated transistors were regressed. Voltage adjustments at R809 were made to 35.04VDC.

Before Re-work

P700

The amplifier board was all stock and untouched, a lot of debate went on about films, the greens and browns I like to keep, but the coupling capacitor C701 had several options, so far its still original, but stack, or a PP would be excellent as were suggested to me. All the electrolytic were replaced with Nichicon FG's and Silmic II's at C707/706/C703. C710/C711 ceramics in the feedback stage and C713 were replaced with C0G/NPO's type. A service bulletin was performed replacing H718/719 VD1122 diodes with single 1N4148's. All the TO-3 mica insulators were replaced and regreased,a long with the top mounted diode. Offset was monitored and set at 0.001-VDC left and right and idle current adjusted to 20mv across. Initially the bias pots R740 were damn near stuck in place but with some faithful D5 and some action I got it too adjust properly. I want to thank Ben here for the simple suggestion going CCW and bring it up DBT at half the VAC, good trick.

P400
As with most of the other boards it was stock as well. We have several diodes to update here also. The axial was replaced with a 220uf Nichicon axial, with Silmic IIs at C403/404. Tantalums C401/402 were replaced with  ECQ stacked film.
Varistor H409 a VD1212 was replaced with two 1N4148 diodes in series and heat-shrinked and insulating the legs.  H408/407  2473's with a single 1N4148. The prone to noise H405/406 2SC458's were replaced with the common KSC1845 transistor.

PE01
All the electrolytic were replaced with Silmic II's and Nichicon FG's. CE37/38 were replaced with bipolar MUSE ES capacitors. The tantalums were replaced with polar FG's. Signal ceramics were replaced with C0G/NPO at CE07/08. CE05/06 where left at this time, though some PP could be used here I think with nice results. All the Pots were cleaned and treated at this time.

PH01
Where signals are converted and passed to the dolby. All the electrolytic were replaced with Silmic II's and a Nichicon FG at CH13. The varistor VD1222 at HH11 was replaced with two  1N4148 diodes in series and heat-shrinked, insulating the legs. PL01 the Dolby, tone and meter board, the electrolytic were replaced with Silmic II's.  The meter capacitors were also replaced with same value Silmics.

N.S.