Charles’ Yamaha CA-810 Int Amplifier

This Yamaha CA-810 integrated amp was sent in for evaluation and some restoration work. It was found that the left channel was clipping slightly quicker then the right. Overall the unit is incredibly clean with no cosmetic defects. The amp has a differential controlled offset so there is no adjustment for DC offset. The bias […]

Juan’s Fisher 500c coupling caps and grid resistors

Here is a before and after shot of an ongoing project restoring a Fisher 500c. The original 0.047uf/600v and 0.047uf/400v coupling caps were removed and replaced with 0.1uf/600v Vishay polypropylene “Orange Drops”. The grid resistors which were 320k ohms were removed and 200k ohm metal film resistors were put in its place. Next up for […]

Leslie’s Pioneer SX-1010 Completed, ready to go home, photo heavy

This receiver is all set to go home and be enjoyed. The amp section had capacitors and 2SC1451 transistors replaced. TO3 output transistors were removed from heat sinks, tested, thermal grease reapplied, and reinstalled. Controls were bathed in deoxit especially the source buttons which were causing distortion. Here is a photo collection of all sections […]

Leslie’s Pioneer SX-1010 Restoration

This Pioneer SX-1010 receiver is almost complete. Here are a few shots of the rebuilt power supply, protection circuit, and FM muting boards. The power supply as expected takes the most time and care as the most components are replaced especially all transistors. Careful attention must be spent on transistor pin outs as the modern […]

Leslie’s Pioneer SX-1010 Pre-service check

In for restoration service is Leslie from Long Island’s Pioneer SX-1010. This is a one owner receiver that is in excellent condition and will be having a very thorough restoration to keep it reliable for more years of enjoyment. The receiver was serviced once before for noisy controls and it apparently had some power supply […]

Juan’s Fisher 500C Pre Restoration Inspection

Recently I picked up this Fisher 500c from a local friend who wants the receiver completely restored and brought back to factory spec. It is one of my favorite tube receivers with a 12ax7 front end and 7591 outputs. This is one of earliest multiplex FM sections. This restoration will take considerable time and will […]

Pioneer QX-646 repair

Recently a Pioneer QX-646 was dropped off for diagnosing distortion when playing LPs through the phono preamp. The noise was described accurately as a static, crackling noise that was only present in the phono mode and occasionally in aux mode. The receiver was tested for output and then signal path was traced to determine the […]

Marantz 2270 Restoration

A new version of our Marantz 2270 restoration can be view by clicking here. Recently I was sent a pair of Marantz 2270 stereo receivers for restoration work. The receivers were close in serial numbers and in good shape. They were never serviced and both seemed to “work”. After some output testing before service it […]

Pioneer SX-1010 Power Supply

Thought this Pioneer SX-1010 was untouched but after checking out the power supply noticed it had previous service. Two caps and the voltage regulators at some point were all changed. Since these are the weak point of the amp it needs to be overhauled. First all electrolytics removed and replaced with Nichicon PW. All transistors […]

Kenwood KA-8006 refurb complete, needs short diagnosed

Haven’t posted in awhile and need to show a lot of work that has been done. The Kenwood KA-8006 had the remainder of it’s refurbish completed but there is still a short issue in the power supply. Originally the issue was the right channel was cut out and C9 on the power supply was blown […]

Kenwood KA-8006 Power Supply

This post should have been a week ago but would like to start with it to show the path this restore took. Last post about this amp I removed the amp boards and changed the electrolytics, a few common problem transistors, and tested the driver and output transistors. Next stop was the power supply and […]

Kenwood KA-8006 Break down

Parts arrives for the Kenwood KA-8006 today and it was right to work. I haven’t revealed the shiny face and controls yet but they have to come off. The amp disassembles very easily and the entire front panel with control boards sort of folds down for better access to the power supply. The plan is […]

Pioneer SX-636 #2 power supply rebuild

Since my huge parts order will not be here until Tuesday I decided I would put a little time into the Pioneer SX-636 and rebuild the power supply. It will also get upgrades to the preamp, amp, EQ, and amp board but I only had an hour or so. So here a quick rundown : […]

Pioneer SX-838 Lamp replacement

This afternoon lamps were changed in the second Pioneer SX-838 restored on this site. I get many emails about lamp replacement and the difficulty varies by unit and which lamp is out. In this case three dial lamps, the speaker A indicator, and FM selection lamps were out. The dial lamps are all the same […]

McIntosh MAC1900 Preservice

This receiver is from my personal collection and will be done in between any bench work for customers. I purchased this receiver last year with the intent of eventually using it as a preamp for a McIntosh amplifier. This receiver appears untouched original all around but very good cosmetically although a previous owner engraved a […]

Kenwood KA-8006 Preservice Bench Test

Today ran a short bench test on the Kenwood Trio KA-8006 integrated amp. The control pots on the amp were very dirty so to start I needed to clean them well to avoid the distortion they were creating. Once clean I noticed a very tell tale sign of something wrong. After five minutes of idling […]

Kenwood KA-8006 Preservice inspection

So as the one component goes to break in and almost ready to go home, another steps up on the bench. Next project is a Kenwood KA-8006 integrated amplifier. This is from the Kenwood-Trio era and is a little powerhouse at 70wpc into an 8 ohm load. This amp resides locally and will be returned […]

Pioneer SX-838 #2 Boards refurbished, testing, and listening test

All PCB work is now complete on second Pioneer SX-838 receiver. Faceplate was pulled, control board had electrolytics replaces along with tantulum caps. All controls were cleaned well and lubed. The balance control causing distortion was the original issue the owner had with the receiver. The dial glass was not secured in the faceplate as […]

Pioneer SX-838 #2 Almost complete

After some extensive work the Pioneer SX-838 is almost sonically finished being restored. The power supply, EQ, protection, and power amp boards were recapped with Nichicon premium electrolytics and Panasonic ECQ film for low capacitance caps. On the power amp board the 2SC1451 and 2SA726 transistors were pulled and replaced with modern equivalents. To gain […]

Pioneer SX-838 #2 Power supply, EQ, and protection before

It’s been a little while and a short vacation since posting work. There’s a lot of pics to show of work and I will try to post some in the next few days. Next up ready for its new parts is a Pioneer SX-838 that will be restored and sent back to its owner who […]