Chevin Amp Repair

[oligoon]

I need to get a Chevin A1000 and Q1004 repaired - any suggestions?

 

 

[timsabre]

Cor, that is a blast from the past. Some of the Chevin amps had a proprietary switcher circuit in them which was encased in resin so pretty much impossible to fix that part - but if an output fault that was just normal mosfets - what is the fault?

Edited December 5, 2023 by timsabre

[oligoon]

the A1000 started to go intermittent on one channel and then that channel failed completely.

the Q1004 lost one side (2 channels out of 4) and blew a fuse - replaced fuse but no life on that side.

 

from your comments I assume chevin is no longer going?

 

[Jivemaster]

Chevin-research.com are still searchable on the web. Those lists include dealers in various countries (Europe and more). The listed service agent for the UK is Music Gear Direct NG16 2UZ.  However that's from Bing search, I offer no guarantee that the information is current.

I used to use a Chevin A500 at that time it was the only amplifier that was a one hand carry with ease.

[DrV]

Regarding the one which went intermittent to start with, that might well be an internal connector. If you're comfortable doing so, it's worth opening it up and removing and reseating any connectors, preferably with a blast of switch cleaner too. Do them one at a time and be very careful to put them back the right way round and in the right place!

The one which has blown a fuse is very likely to have a shorted output stage so is definitely not a DIY fix.

[timsabre]

We were involved with the design of the Chevin amps and Chevin Research has not existed for probably 15 years.

Most likely fault for the intermittent channel is the gain pot failing. Also they had a weird home made optical limiter (LED and LDR in a heatshrink tube) which sometimes got muck in it.

As Dave says the other is most likely output stage transistors, but that part of the circuit was a fairly conventional mosfet output stage.

[Jivemaster]

Chevin Research probably still exists otherwise their www hosting would be expired by now. I've visited their site today (06/12/2023) their contact details are on the site,

Address: Slovakia, Phone: +421 915 292356, http://www.chevin-research.com

United Kingdom Dealer/Distributor, Nottinghamshire, Music Gear Direct +44(0)1159383892

 

 

[timsabre]

Ah you're right. clearly they sold the designs to someone in Slovakia! They must just be making the old designs though.

[Yorkie]

On 12/5/2023 at 6:58 AM, oligoon said:

I need to get a Chevin A1000 and Q1004 repaired - any suggestions?

If you put your location in your profile, you may get more relevant recommendations

[Jivemaster]

Music gear direct will look at Chevin amps.

re Yorkie; Chevin (now in Slovakia) seem to have one contact for the UK who didn't sound very hopeful on the phone. 

[Yorkie]

Whilst there are brand specialists and service centres, I suspect there will be someone within an hour's drive of most of the UK who has the relevant diagrams and is used to repairing amplifiers of different makes

[Jivemaster]

Chevin's prime advantage when new was light weight. Largely due to switch mode psu's. Having stock of the internal modules that were cutting edge in the 90s could be the difference between repair and failure 30 years later.