This Rose RV23 preamp dates from the 90s. As standard, it already sounds good and it came to me a few years’ ago for some upgrades to the power supply, and improved coupling capacitors. With those mods it sounds really special!
This time it was in for a new volume pot, and selector switch, along with a couple of new phono sockets as the originals were very loose. A TKD pot was chosen along with a quality Elna selector switch and teflon /gold plated phono sockets. I always enjoy listening to this pre which you’d have to spend several thousand pounds to beat! No circuit digram is available and no one is even sure whether the valves should all be ECC82s or a mix of 82s and 83s…..it works with both!
It’s not every day that a pair of amps costing £23k arrive in my workshop but I have come across Shindo equipment a few times in recent years. Very iconic, high level, hand built Japanese hi fi for those with plenty of cash. These mono blocks have many things I hold dear to heart, such as parallel single ended operation and zero feedback. They are also specially voiced using some NOS valves and capacitors in key places. Nothing too seriously wrong with these boys, they are in for a check over and rebiasing.
The retro green styling I guess will please some and leave others cold. It has grown on me over the last week! And they certainly sound beautiful, being close in character to my Mastersound 845 PSE mono blocks!
As the photo below shows, build quality is exemplary.
I recently completed a mains powered Little Gate step up amplifier in black. Some folk ask what the difference is between the mains and rechargeable battery versions and the answer is very little but the mains unit pips the rechargeable version for a little bit more weight and authority. An earth lift switch provides for hum free operation in different systems.
I was commissioned bu a client to mount some Hashimoto step up transformers in a small case and this was the result. Small and neat, with the transformers top mounted to minimise real estate taken up by them. On the rear there is an earth lift switch to ensure hum free installation.
This Radford TT100 came to me in a dangerous but semi functioning state. Some folk seem to enjoy a dangerous life, otherwise how else do you explain high voltage components loosely attached to the chassis with Blue Tack? This big Radford carries 680v HT, and that’s definitely a lethal voltage. Yes, HT on spec is 600v but my mains is the highest permitted here at 253v ac, and the extra 10% is rated up by the HT supply along with tolerances. First task was to make the amp safe just to test if it worked-it did just about-and then the slow process of restoration began. The client wanted a great sounding amp for everyday use, not a restoration to exact original condition, which was a great challenge.
This was one amp I could not wait to turn on and test after completion. And it didn’t disappoint. A lazy silky smooth power with massive bass underpinning, just sounds delightful through my Tannoy Canterburys!
This 50 year old amp had been recently fitted with some NOS valves and even before any work sounded very decent. From inspection, it looked like it had had one service in all the years, at which point the main smoothing capacitor was changed. Bradford introduced the STA15 for those who didn’t want the hassle of manual bias and despite the STA15 nomenclature the amp pushes out over 20 watts.
The work agreed with the owner was to change all the electrolytic, upgrade the coupling capacitors and to use Elna Cerafine capacitors for cathode bypass duties. We also agreed to renew the input and valve socketry along with the valve riders.
The link here gives further details and the owner’s reaction to the results. Radford Restoration
It’s been a busy few weeks and the following are just some of the latest amps in for restoration, repair and upgrades. A Radford STA25 is in for repair and upgrade and is having new main electrolytic caps fitted along with upgraded cathode bypass and coupling caps and new bias pots.
I am doing a major restoration job on a Radford TT100. This is a very interesting solid state input /tube output hybrid producing 100watts a channel. A previous owner had made many mods, and left the amp in a dangerous state with 680v components held on with Blue Tack. There had a also been a major blow out on one channel which had taken out the driver transistors and bias pots on one channel. A further mod had been an attempted change to a choke input power supply but without changing the inductor. So the HT was around 100v down!
A McIntosh MA 7000 came in for new main psu caps and rebiasing.
Some Hashimoto step up transformers are in to be mounted in a decent case and wired up.
A Mastersound Dueveinte is in for the addition of a tape out socket, and a few other upgrades.
A Yaqin MC13 has been in for coupling capacitor upgrades.
And again a few Audio Innovations S500 have been in for upgrades, repair and servicing. Finally, a Copland CTA401 has arrived for repairs and servicing.