Saturday, 27 August 2022

For sale: THETA DSPro prime digital processor

For sale: REL Acoustics Strata II 60W Sub Bass System


For sale: ROTEL RCD-950 Stereo Compact Disc Player


For sale: KEF R400b Sub-Woofer 110V Only


For sale: MISSION 752 2-Way Tower Hi-Fi Speakers in Black Ash


For sale: DENON POA-2800 Stereo Power Amplifier


For sale: DENON TU-280R AM-FM Stereo Tuner


For sale: DENON DAP-2500 Digital Audio Pre-Amplifier


For sale: DENON DRM-510 Stereo Casette Tape Deck


Saturday, 20 August 2022

Boston Acoustics A26 Bookshelf Speakers


The A 26 6.5" 2-Way Bookshelf Speaker from Boston Acoustics offers high-quality audio in a stylish and modern design.

The cabinet has a high-contrast finish with scratch-resistant glossy panels, a textured top, and a magnetic grille to fit beautifully into any décor. 

The advanced 6.5" ceramic/glass fiber polymer woofer has Deep Channel Design technology to deliver plenty of bass response from little amplifier power.

Acoustically tuned bass ports on the cabinet also help to extend low frequency response. 
The 1" Kortec soft dome tweeter provides crystal clear treble frequencies.

Horizontal and vertical internal bracing reduces in-cabinet resonance for enhanced audio quality.

High-quality components include crossovers with low-loss film capacitors and inductors with low-distortion laminated silicon steel cores for enhanced sonic performance and reliability.

The rear panel features gold-plated 5-way binding post connectors to provide terrific hookup flexibility for a variety of home theater and music systems, perfect for stereo or surround applications.

The connectors also provide pure signal transfer for the best audio experience possible.


Saturday, 13 August 2022

Peavy 6505 Guitar Amplifier On The Bench

 This poor Amplifier gave itself a hard time..

Too many components faulty. Mainly electrolytics.
The main resistor supplying the BIAS voltage to the Output Tubes (6L6GC)
changed value under load conditions.
It was replaced with a Bourns 20 turn potentiometer.

The 6.3V AC from the mains transformer burnt out (don't ask...)
and a standby transformer was used to drive the filaments of the phase inverter and output tubes during these tests.

The Amplifier has now been in full operation for > 4 hours. There is hope.

Most of the electrolytics have been replaced. Some resistors burnt out and was replaced.
Added a Bourns 20 turn POT for R108 (5.76K)
That allows for the adjustment of the voltage drop across the resistor (current) that
supplies the BIAS voltage.
Glued the Bourns Pot with Pratley Clear quickset.|
(Tested before it got dry. NO conductivity.)

Adding another transformer (6.3V~ 20VA), to supply power to the relevant tubes should do the job.

Some pics of the inside...

Wednesday, 10 August 2022

Steve Vai Live (2008)


Sorry about the poor quality.

I just got reminded about Guthrie Govan. Great guitarist.


NAD Stereophonic Amplifier Restoration (1973)

 NAD Service 9 Aug 2022

Approximately 7 hours work.

I don't count.

Full cleanup, contact cleaner, blow dry.

Replacing 13 electrolytic capacitors.

6 800uF with 10 000uF on split power supply. (Had to drill some holes.)

Replaced germanium bridge diodes with 1N5408 3A 1000V

Replaced 2N3055 output transistors with RCA (to match 2N2955 and due to corrosion.)
Re-calibrated power meters.

Glued mains broken socket. (Did not try to get a new one).

To do BIAS and DC offset adjustments require soldering resistors on the back of the board.

I will check the current values. If they are OK then I won't delve into that as well.

It's quite a laborious task. Let's not split hairs.

Full check... Especially decoupling resistors for differential input stage.

The Amplifier is done.