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Need a schematic for an L795RV [message #5328] Tue, 11 January 2005 19:26   chacuff Messages: 11 Registered: January 2005 Location: Gulf Coast Junior Member Hey Folks, I'm new here and to Kustom Amps. I do own a couple vintage Fenders and I'm a just starting out as a player. I'm mostly a 48 yr. old Technician. I picked up an L795RV setup. It is a 1967 model judging by the S/N. A frankie I have learned from reading on the web. It has the 2-15 JBL cabinet with the original JBL speakers intact. They seem to work fine..no dragging or buzzing. The amp works fairly well on the clean channel but has no volume on the reverb channel. I can tell that the reverb pan is working but the vibrato is not. It's clean on the inside with no components visibly burned or what not... I need to locate a schematic for it so I can get started on getting it back in shape. I'd like to see it working properly again. I am not sure which amp was included in the 795 system...am I even close in guessing a K-200A-2. Anyway if you could point me in the right direction I would appreciate it! Thanks... Cecil... Report message to a moderator

Re: Need a schematic for an L795RV [message #5331 is a reply to message #5328] Wed, 12 January 2005 08:35   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member Hi, I have a schematic that will work for that. mail me a self adressed stamped legal size envelope, and I will get you out a copy. steven magnotti p o box 1160 yorktown ny 10598. Report message to a moderator

Re: Need a schematic for an L795RV [message #5336 is a reply to message #5331] Wed, 12 January 2005 11:50 chicagobill Messages: 2005 Registered: April 2003 Senior Member Hi Cecil: Welcome aboard! It won't be too long before you're as hooked on tuck and roll as the rest of us. The Frankenstein heads are an entirely different design from the later 200's. A couple of the major differences are that the power amps use a transformer to drive the output transistors, and the vibrato (true-pitch shift) is controlled by a photocell and light bulb combo. I have rebuilt a couple of my own 95RV's, and I will be glad to share any insight that I may have gained from my experiences. Once again, welcome! Bill Report message to a moderator

Re: Need a schematic for an L795RV [message #5341 is a reply to message #5328] Wed, 12 January 2005 15:35   chacuff Messages: 11 Registered: January 2005 Location: Gulf Coast Junior Member Thanks Guys for your help! I will have a self addressed stamped evelope in the mail in a day or so. I will also probably have some questions as I go through this process so I'll thank you in advance for the help! Cecil... Report message to a moderator

Re: Need a schematic for an L795RV [message #5347 is a reply to message #5328] Thu, 13 January 2005 12:53   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member It sounds like you will need a way to inject a test audio signal into this channel from its output back to the front end, unless you get lucky, and just have the feed cable to the driver board come off like I did on one k200. Report message to a moderator

Re: Need a schematic for an L795RV [message #5351 is a reply to message #5328] Thu, 13 January 2005 14:19   chacuff Messages: 11 Registered: January 2005 Location: Gulf Coast Junior Member Hey Steve, I have a fairly well equipped shop with a Sound Technology audio analyzer that generates an audio signal and then will take the output of the amp and terminate it into a 4,8,or 16 ohm 250 watt load bank. I can then clip my O'scope on the output and see what the signal looks like. I can also step through the circuitry with the scope and find where I am loosing the signal. The analyzer can measure the RMS power output and the IM distortion, signal to noise ratio and all the neat stuff you would be interested in if you were repairing a stereo system amp. Should work great for the guitar amp. I'll let you know how it goes.. Cecil.. Report message to a moderator

Re: Need a schematic for an L795RV [message #5358 is a reply to message #5328] Fri, 14 January 2005 12:56   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member Have at it!!! Report message to a moderator

Re: Need a schematic for an L795RV [message #5451 is a reply to message #5336] Fri, 11 February 2005 03:32   Kustomgonewild Messages: 2 Registered: February 2005 Location: NC Junior Member I was wondering if chicagobill had a schematic for a L995 Frankenstein head and how I could have it arrive at my address. Also, I was curious about the ohm-age of the L995 because it pushes a 3/15 cabinet. Report message to a moderator

Re: Need a schematic for an L795RV [message #5452 is a reply to message #5328] Fri, 11 February 2005 08:46   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member The 3-15 cabs are wired for 5.3 ohms (3-15s at 16 ohms in para). the amp can drive down to 4 ohms fine! Report message to a moderator

Re: Need a schematic for an L795RV [message #5456 is a reply to message #5451] Fri, 11 February 2005 13:05 chicagobill Messages: 2005 Registered: April 2003 Senior Member KGW: I have the same schematic that Steven has been so nice to distribute. All of the "95" or Frankenstein heads use the same schematic, as the heads are all the same. Some came with no FX, the PA's came with reverb only, and the rest have reverb and vibrato. The reason for the different "model" numbers (595, 695, 995, etc.) was the list price of the amps including speakers. Check out the catalogs in the literature section and you'll see how it works. If you e-mail me your address, I'll send a copy of the schematic, or if you send a SASE to Steven, I'm sure he'll send you one (see his Jan.12th post). Also, you can check the technical section and see if there is a copy available from the nice folks that bring us this great webboard. Bill Report message to a moderator

Re: Need a schematic for an L795RV [message #5458 is a reply to message #5456] Fri, 11 February 2005 13:32   chacuff Messages: 11 Registered: January 2005 Location: Gulf Coast Junior Member Bill, Will you include me on that email of the schematic. Mines on the bench waiting and I could get started this weekend. Thanks... Cecil chacuff@cableone.net Report message to a moderator

Re: Need a schematic for an L795RV [message #5469 is a reply to message #5328] Tue, 15 February 2005 08:23   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member I am sending you out the frakie schematic today.Hope it helps you. Report message to a moderator

Re: Need a schematic for an L795RV [message #5470 is a reply to message #5469] Tue, 15 February 2005 09:01   chacuff Messages: 11 Registered: January 2005 Location: Gulf Coast Junior Member Thanks to both Steven and Bill for the help...It's much appreciated. I'll let you know how it goes. Any common failure items in these amps I should be aware of....blown input transistors, leaky caps. Of course I have found a leaky cap or two already but none that are causing the major symptoms I'm having. I expect to find a few bad transistors in the early stages but haven't gotten to that yet. Thanks again guys... Cecil.. Report message to a moderator

Re: Need a schematic for an L795RV [message #5473 is a reply to message #5470] Tue, 15 February 2005 14:58 chicagobill Messages: 2005 Registered: April 2003 Senior Member Cecil: The only common problem that I've seen with the 95 series heads, is that there is a high failure rate of one type of cap used on the driver/regulator board and the FX board. It is a 500 mfd. cap with a black molded plastic case, about 0.5 in. dia. and about 2 in. long. Most of them have dried out and opened up, or have dropped in value. What are your amps problems? Bill Report message to a moderator

Re: Need a schematic for an L795RV [message #5475 is a reply to message #5328] Wed, 16 February 2005 08:48   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member I opened mine up last nite, and your right bill, in fact their are 2 of those type eletrolitic paper case caps in the amp. Back when these amps where made, their life span was 5 years, and between 5 to 10 years was great, so now they have to go!From looking at the detail notes on the schematic, model wise, 96000 was the standard bass or guitar head with no effects,96001 is the guitar model with reverb and tremlo, and 96002 is the PA head with reverb.And they seemed to be picky about the grade of 2n3055 regulator and output transistors that got put in the amp.Makes sence, back then transistors rated for around 100 watts where new tecnology and they where not to well matched at times I guess. Report message to a moderator

Re: Need a schematic for an L795RV [message #5477 is a reply to message #5475] Wed, 16 February 2005 14:51 chicagobill Messages: 2005 Registered: April 2003 Senior Member Steven: As I recall, you own a 95 PA version head with just reverb, right? How are the input jacks on your amp wired? Are the two inputs for each channel wired in parallel or are there isolation resistors? Bill Report message to a moderator

Re: Need a schematic for an L795RV [message #6732 is a reply to message #5328] Thu, 02 March 2006 22:33 jerryp Messages: 5 Registered: March 2006 Location: Syracuse, NY Junior Member Any chance someone could email me the L795RV schematic? FJAMods@aol.com I have one on the bench and could really use a schematic. Thanks! Jerry Report message to a moderator

Re: Need a schematic for an L795RV [message #6735 is a reply to message #5328] Fri, 03 March 2006 07:43   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member I can fax you one if you let me know before 3 pm EST today, friday 3/3. If not I can fax it next week. Report message to a moderator

Re: Need a schematic for an L795RV [message #6736 is a reply to message #5328] Fri, 03 March 2006 07:49   stevem Messages: 4736 Registered: June 2004 Location: NY Senior Member I would plan on having at least one of the 500 mfd at 50volt caps on hand when you get into it, and two of them if the amp has reverb. also 2 or three 2n3055 TO3 transistors, or the NTE130. Report message to a moderator

Re: Need a schematic for an L795RV [message #7249 is a reply to message #6735] Sun, 30 July 2006 21:47   scottyallen Messages: 5 Registered: April 2006 Location: West Point, Mississippi Junior Member Hello Steven: I am a friend of Deb Hart's "KustomBlues". Could you fax me a schematic for the L995 Bass Head? Just got it and it has a LOUD Buzz... Scotty Allen fax 662-494-5402 email: allenscotty@hotmail.com Report message to a moderator

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