Comments for ivanrichards

Comment on More about Rivera amps: the ‘Ninja Boost’ MOD by Marco Sabattini

Marco Sabattini — Tue, 21 May 2013 15:19:53 +0000

Hi guys, maybe it’s not a big mod for slavemaster “channel”, however it just open things when you change c403 from 120pf to 47p (see Rivera M Series schematic here http://www.prowessamplifiers.com/schematics/misc/Rivera_Knucklehead.html ), it’s the cap between negative input and output of the first opamp in this circuit. Also replacing TL072 chip with an RC4559 may help to get some brighteness from this “muddy” (at least for me) onboard overdrive. I’ve noticed that my M60 had 120pF, maybe some later revisions have a 47pF already. The only defect I’ve noticed it’s just a little noise from the new opamp..at loud volumes.

Boost on the gain channel it’s difficult to achieve (it’s a double face pcb circuit, damn..) however it can be pleasant to add a bright switch on CH1 Volume. Just sold a wire from the lug of C104 connected to the 1M volume pot (take care of shielding) and install a switch on the back to open/close a contact for a silver mica 500pF cap soldered to the center tap of the volume pot (I’ve done it soldering it to a lug of PH101, follow the schematic above). Essentially you get the same function you have on CH2 when you pull out the treble pot. Have fun and take care of the same recommendations on voltages, shielding, etc..or just refer to an expert tech ;D

Comment on More about Rivera amps: the ‘Ninja Boost’ MOD by samsavvas

samsavvas — Tue, 21 May 2013 00:25:38 +0000

Hi Ivan and Marco,
Ivan – thanks for outlining the boost volume mod. Will have my techo install it for me.

Marco – I’d very much like to see your ‘slavemaster’ channel mod and read a bit more about it. Have you documented it somewhere or can you provide more details? I have an R-55.

thanks,
Savvas

Comment on More about Rivera amps: the ‘Ninja Boost’ MOD by rockon1@optonline.net

rockon1@optonline.net — Thu, 11 Apr 2013 22:26:33 +0000

How about a boost mod for the gain channel? Most of my playing is done there and it would be extremely helpful. TIA Bob

Comment on VHT Pittbull Classic by ivanrichards

ivanrichards — Thu, 21 Mar 2013 09:59:39 +0000

hello Stephen. Please contact me direct to discuss specific amp repairs. Thanks, IR. info@ivanrichards.com

Comment on VHT Pittbull Classic by stephen poulton

stephen poulton — Thu, 21 Mar 2013 03:34:47 +0000

can you help me with 115 to 230 volt transformer rewire?

Comment on Another ZJM amplifier in our workshop. by Paul

Paul — Wed, 13 Mar 2013 00:40:08 +0000

I purchased a Vedette (60w) similar to the one at the top of this page in the early 70s and still use it from time to time . The head is in very good nick ( internal/external/sound) and just got its serviced a couple of years back by a valve specialist . The valve guy said it was a rare beauty and well worth insuring for a value which I did . He said they just dont make transformers that good anymore. it was very well and tidely wired compared to another he had seen years ago. It is now back in safe storage . Unfortuneately the matching speaker cabinet and speakers fell apart years ago. I instead play the vedette through a fully enclosed black vinyled speaker cabinet my dad abd I lovingly built together in 1973 encassing 2 X 12” Plessy 12U50s..Great full tone /sound . Although i have no intention of selling soon does anybody know how much a vedette 60w head in good condition would be worth ? Paul .

Comment on More about Rivera amps: the ‘Ninja Boost’ MOD by Gwen

Gwen — Fri, 25 Jan 2013 08:42:26 +0000

Hi ! Thank’s Ivan , for this mod ! I would be interested by the “slavemaster” mod , Marco .

Regards .
Gwen

Comment on MOD for the David Eden WT800 bass amp by ivanrichards

ivanrichards — Wed, 23 Jan 2013 11:56:12 +0000

hello – we are located at Gosford on the NSW Central Coast. Workshop address: Ivan Richards Audio, c/o Eagle Business Park, 1 Frances Parkes Close, Wyoming, NSW 2250, Australia. To maintain the highest level of customer service, we prefer customers to attend the workshop by appointment. Phone 0418 862 034. International 61 (0)418 862 034.

Comment on MOD for the David Eden WT800 bass amp by Stanley Whitehouse

Stanley Whitehouse — Wed, 23 Jan 2013 07:27:32 +0000

Hi Ivan …
It’s pretty cool that you have taken & improve the Eden WT 800
and as an owner that has had hicks fixed am interested what the cost Wouk be for you to MOD my amp maybe one day ..
Where are you located?

Just an enquiry
Regards
Stan W

Comment on A very rare Marshall JMP by Mark Ferrer

Mark Ferrer — Tue, 08 Jan 2013 17:56:16 +0000

I’m having a heck of a time getting replacement matched ECL86 tubes. If anyone knows of a source, please let me know, much appreciated.
I have the 2-10 version, 1970 and love it for a home practice amp. highstrungguitarshop@yahoo.com
Thanks, Mark