Stuart Watson

Sorry I can't help with the port rings.They were an embellishment that came later on.

I can probably answer most of your questions relating to Trace Elliot products made between 1978 and the end of 1986.Fred Friedlein (MD),Alan Morgan(sales) and I (designer) were the founder members of Trace Elliot.designed all models up to then including GP 11 preamp, GP7 preamp and the AH 150 combo amps.

The amp heads AH150,AH 350x,the biamp model and the most popular AH250 and AH500 heads.

Stuart Watson.

Late eighties  to mid nineties.We stopped production as we were more than fully stretched with a contract with a major electronics marketing company.Added to this, the trend amongst bassists at the time was moving back toward retro style simple valve amps.

Some pictures of Decimax from advertising leaflets.There was also A 1 x 12 guitar combo. The last picture shows Chris Childs with a D 600 rig.Chris currently plays with Thunder.

On 12/10/2019 at 17:17, John field said:

I’ve got one. It’s a D600. I think it’s 600 a side. Beast of an amp and weighs a ton. I’m getting it serviced to sell on as I don’t use it. I’m a guitarist and it was used in my studio room for bass players to use. Never seen another so obviously really rare.👍

I can throw some light on  the Decimax subject.I designed these amps after leaving my post as Technical director of Trace Elliot.I designed the original Trace Elliots and all subsequent ones up to the mk 5 series. Decimax amps had programmable graphic eq and levels plus a midi interface to control  and memorise any external effects along with your chosen eq and level.A separate smaller manual graphic allowed for tweaking to compensate for room acoustics without needing to re programme your settings.Main models were D300 and D600  which were 300 and 600 watts respectively.  Speaker cabs were either 1x 15 or 4x10.Both featured rear porting.These amps had no connection with Carlsbro at all and were built at our factory in Essex.