Tuesday, June 28, 2016

Marantz 1060 Integrated Amplifier 

Today we are showcasing a Marantz 1060 Integrated Amplifier.  The Marantz 1060 is by far one of the most well regarded Integrated Amplifiers of the period, highly sought and prized for its simple, yet extremely mellow, smooth sonic qualities.  Sharing a similar topography of the pre-amp and a simplified 35V regulated power supply to the Receiver variant the 2230.  Paired with something like the Marantz Imperial 6 speaker system and a nice turn table or line source and you have yourself a classic slice of Americana’ Hi-Fi! On this particular rebuild we laid an emphasis on polypropylene upgrades within the coupling/input points.

Power Supply P900
The regulated power supply consists of a simple BJT regulator and filtering network for the 35V RIAA and 27V line level circuits.  After depopulating the assembly its important to carefully remove as much of the glue debris as possible, replacing and cleaning any effected components.  

After cleaning of the PCB is done, all of the electrolytic were replaced with a high temp (105C) Panasonic FC capacitor’s. The original ceramic .01 bypass caps were replaced with a 630V .01 Panasonic ECW polypropylene and the tied 1S- type diodes replaced with a Ultra Fast UF 400# type diode. The regulating BJT 2SC1213 was replaced with a 2383 BJT.

The remaining AC filter 4700MFD capacitors was replaced with a low ESR Nichicon up to a 10,000MFD value and coupling 3000MFD capacitors replaced with two low ESR Nichicon 6800MFD capacitors for an improved bottom end and better rectification filtering.  For hardware sakes we replaced the original switch at this time as well as then tend to gum up and arch resulting in failure.  A new DPDT 7A 250V power switch with a X1Y2 Vishay safety capacitor was installed and fixed to the chassis. 

Pre-Amplifier P400
As mentioned the 1060,2230, 2245 and 2270 all share a very similar topography.  On this assembly we updated all of the NPN small signal transistors of the (GR) grouping 2SC1000 devices to a compliment of new KSC1845 transistors.

The input and output coupling films of .22 and .47MFD electrolytic and mylars were upgraded to a high grade MKP polypropylene film capacitors.  Remaining electrolytic were replaced with audio grade Nichicon KA/ Fine Gold capacitors. The coupled BiPolars were replaced with a 1MFD high grade Panasonic ECW polypropylene film capacitor. 

 In front of this assembly is the tied tone control network, which I advise pulling now to properly clean the tone and volume/balance selector potentiometers and switching. 

The Marantz 1060 has an infamous phono stage, with a very linear and responsive curve and large compliment of polypropylene the RIAA has one of the best sonically designed, NPN gain staged  phono stages out there in my honest opinion.

As with many of the integrated and 22XX series Marantz, the 1060 utilizes the 2SC458 which is a notoriously bad transistor, known for noise potentials.  Small signal transistors 2SC1000 and 2SC458 were updated to 1845 compliments and H905/906 (458) matched to 1%.  The remaining electrolytic were replaced using  all Nichicon KA audio grade capacitors and original .47MFD films to a high grade MKP polypropylene film capacitors.

Drivers P700
 Using a single PCB symmetric topography the 1060 comprises the differential with a single 945 BJT, through pre-drivers and multiple circuit H705-708 and drivers H709-712 to a quasi complimentary pair of outputs.   The .47MFD input electrolytic were replaced with a high grade Panasonic ECW polypropylene film capacitor and output coupling to a 1MFD MKP polypropylene film capacitor.  Remaining electrolytic were replaced with  high temp (105C) low impedance Nichicon PW capacitors.  Both offset and bias potentiometers were replaced with precision bourns trimmers as well.  Both SVT thermal diodes and TO-3 devices were pulled and new thermal compound applied.  Bias was calibrated at 15mV VS SM detail. 

Audio Notizen

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