Repair Log: Roland Space Echo – Chorus Echo RE-301 SN: XXXXXX
Log last updated – 02/02/18
Copyright retained by Terry Relph-Knight
Value – £100, They can be found for £155 in very good condition (which this one isn’t)
The Roland Space Echo RE-301 tape loop delay has a sound-on-sound playback head and three delay playback heads. It also has a built in BBD chorus and a spring reverb.
Note – The Roland user manual says – ‘Wow and flutter is minimised by the use of a free running system, which also serves to extend tape life over 300 hours.’ So tape loops still need to be changed relatively frequently.
After a lot of investigation it looks very much as though this unit has been patched together out of two or more broken RE-301s and possibly further ‘repairs’ have been carried out over the period it has been in use.
Front panel controls are –
Metering – Peak level LED, MC VU meter
Input mixer – 3 x Input level rotary controls, -20 -35 -50dB slide switch and three ¼ inch input jacks.
Direct signal on/off slide switch – Switches between Wet and Dry mixed or Wet/effect only.
Chorus – Intensity control, indicator LED, Chorus on/off via push button or remote jack
Echo – Indicator LED, Echo on/off via push button or remote jack, 6 way mode switch for playback head selection, Sound-on Sound toggle and remote jack, volume, repeat rate (with a remote jack) and intensity controls, a toggle switch allows switching to single delay regardless of the setting of the intensity (regeneration) control. At some point this switch has been replaced with a three way centre off switch.
Reverb – Volume control
Output – Bass and Treble controls, -15,-25,-35 dB three way level slide switch, A (A+B) and B output jacks.
Power toggle switch, VU meter illuminates when power is on.
Head order (left to right)
Sound on sound PH4, Erase head, Record Head, PH1/Mode1, PH2/Mode2, PH3/Mode3
(Visually the azimuth on S on S, PH2 and PH3 looks off).
Problems – In just for a general check over and alignment. The electronics seem very temperamental, it seems to act differently every time it is turned on. For example on one occasion echo modes 3,5 and 6 passed little signal with lots of hum. One another occasion, when first powered up the regeneration did not work, then with some control fiddling it came to life. The Chorus makes a sort of on/off gargling sound. The spring reverb just hums. Even switched off the RE-301 hums when plugged in to an amplifier indicating a ground problem somewhere.
Periodically the tape slips so the echo produced is not constant and regular. I now think this is entirely down to the tape loop. Even though the MTE replacement loops I bought are supposedly manufactured for the Space Echo I don’t think they are of good enough quality.
All but one of the original M3 thumb nuts (supplemented by one ordinary M3 nut) that secure the acrylic plate over the tape loop bin where missing. These were replaced with 5 stainless steel M3 thumb nuts.
Dirt and old tape oxide were cleaned from the tape bin, the head plate and the top surface of the unit. The two felt tape pressure pads were cleaned of dirt and oxide. The pinch roller was removed, cleaned with isopropyl alcohol, the centre bearing lubricated and the roller replaced. NOTE – All rollers and pads now replaced.
The hard rubber pinch roller has a sintered bronze sleeve bearing mounting onto a polished steel shaft. It is secured by an M3 screw that has a small spring washer, a larger plain washer and then there is a felt ring to capture any excess oil. The screw and washers are concealed under a black rubber mushroom push-on cap. The head of the M3 cross head screw holding the pinch roller was quite chewed up so this was replaced with an M3, stainless steel, hex button head screw.
The feed roller bearing on the other side of the tape path was removed cleaned and lubricated (now replaced). The feed roller is held in place by an M3 12mm countersunk cross head screw that passes through an aluminium disc and a nylon spacer that fits in the centre of the ball race bearing used as the feed roller. The ball race bearing is spaced top and bottom by a thin bronze washer.
A new tape was loaded and then the bias trap was adjusted for maximum rejection and the bias level set. All the heads where cleaned with isopropyl alcohol, magnetically degaussed and were checked and adjusted for height and azimuth.
Replaced the VU meter 12V pea lamp with a wide angle white LED fed from an 820ohm resistor.
Unplugged all 16 internal Molex connectors, wiped the contact pins with DeOxit and plugged all the connectors back in.
To fix general hum problems I removed the step down auto-transformer from inside the case and re-wired the echo unit with a long mains lead terminated in the US 110V mains plug. This can now plug in to the auto-transformer sited outside the case.
Glued down all the pealing edges of the Tolex around the wooden case where the original adhesive had failed.
Further problems With the MTE RT-1L tape loaded the unit developed tape slip resulting in pitch wobble. As the only reliable source of Space Echo parts I ordered two service kits from EchoFix.com in Australia. The original order went missing somewhere between the sorting office and my house. EchoFix sent me another set for the cost of postage. I also paid a customs charge on the original shipment.
Each kit contains a new pinch roller, feed roller, a set of friction felts and two replacement tapes. Having fitted all these parts the tape slip problem seems to be solved.
I re-set the bias trap, re-biased for the new tape and checked all the head azimuths. Note – playback from head 3 seems to be half that from the other two heads. There do seem to be level adjustment presets on the main PCB, but I did not adjust them.
Fitted a new TA7200P integrated power amp in an effort to get the reverb to work. Nope sadly not, although the chorus has come back to life.
This unit has either been ‘pragmatically’ repaired, or is a Frankenstein. An etched aluminium plate screwed to the back of the case clearly states it to be a 220V AC unit and indeed it does run on UK mains. However an internal examination shows that a 240V to 110V conversion auto-transformer, supplied by the UK electrical chain Ryness, has been fitted inside the case. This is fed by the external mains cable and the Roland power transformer (which must have a 120V primary – it does, the primary wire colours match those for a 120V supply as shown in the Roland service manual) is plugged in to the output socket of this extra transformer with a large yellow US three pin plug that mates with a socket on the side of the extra transformer.
Either this unit has been cobbled together from a US and a European unit, or the original Roland 220V mains transformer blew and was replaced with an original 110V transformer, making it necessary to add the extra conversion auto-transformer. Which by the way has input neutral (now blue) wired to the right (white, which is US neutral) on the US plug. US live is black and is on the left looking in to the socket. The actual Roland power transformer fitted inside the unit is definitely the transformer designed for 110V input because it has the white (neutral) and green/blue (live ,fused) input wires as specified on the Roland circuit in the service manual. A 240V unit should have a Roland transformer with red (250V), brown (230V) and white (neutral) as the primary wires. The Roland transformer is connected the wrong way round – the green/blue wire should go to the internal fuse.
In any case this extra transformer is mounted right next to the built-in spring reverb tank at the output end of the tank. As a result the reverb hums because the output picks up the field of the transformer.
The spring tank itself had been moved to the right to make room for the auto-transformer and one of the support brackets that holds the case together removed to make room for the tank. The spring tank is an interesting design, an OC Electronics Folded Line Reverberation Device Type 60, apparently “Manufactured by beautiful girls in Milton, Wisconsin under controlled atmospheric conditions” with a folded Z configuration of three springs. The drive and pickup coils are sited at the ends of the Z with the angles supported on resilient mounts. Unfortunately the drive signal for the reverb seems to have gone AWOL, there is audible spring clang if you tap the tank, but no reverb effect. Connecting a 3V light bulb continuity tester briefly across the input coil also produces a crash so the input coil is intact and the delay tank seems to be working. Either the reverb drive amplifier no longer works, or it is not receiving an input signal. The reverb drive chip is a TA7200P, a 3.3W single chip audio power amp in a 10pin SIL package. EBAY £3.08.
The chorus only makes some rather weak wobbling sounds. Adjusting the BBD clock balance and BBD bias trimmers does not bring the clock signal close to the symmetry shown in the service manual. The chorus delay is produced by a MN3004, a 512 stage Bucket Brigade Delay chip in a 14 pin DIL package. These can just about be found on EBAY for £50.
Pilot / VU meter filament pea bulb has blown (has previously been replaced by splicing the wires). Voltage is 13.45V DC. Replaced with a wide angle white LED 30mA max 3.1V drop. 10V 20mA = 560 ohms, hmm I have 820 ohms to hand I’ll use that, seems bright enough.
Unreliable operation – There are 16, Molex 0.15pitch SIL connectors, 5 on the power and bias board and 11 on the main PCB. It appears that these have been unplugged and re-plugged several times in the past and is very possible that these aren’t all making reliable contact. Also the echo mode switch seems very uncertain in its operation. Unfortunately this is a sealed switch.
The power supply is in two sections – a bipolar +14.5V, -14.5V to feed the op-amps and other electronics and a supply for the variable speed servo motor. Pin 1 of IC4 / R406 is labelled – 13.3V (fast) to – 5.5V (slow).
Measured supply voltages are now –
Measured supplies – Minus 13.91V Plus 14.04V
Servo at Pin 1 of IC4 – 6.33 to 12.53V
Basic functionality tests from input to output
All three input mixer channels work and behave identically. The level controls function, the level switches work (there are internal pre-sets to balance the input gains VR15, VR16, VR17). The peak LED and VU indicate as expected.
The Direct signal switch switches the mix of the direct signal on and off. With all the effects off the clean signal sounds reasonably free of hum and noise and is relatively undistorted. The mixed output with the Direct switch on appears on the A+B jack, the B jack is always effect only.
With Direct off and Chorus on the output is vibrato only.
The Chorus switch does switch in an effect, but rather than a smooth swirling chorus, there is a two step phase change sound. It may just be that the chorus circuit trimmers (VR12 BBD bias, VR13 BBD clock balance) need attention or it may be a general power supply problem (having cleaned all the connectors, cleaned the back of the PCB of dirt and flux and set the two trimmers to their centre positions the chorus now seems to have come back to life).
The Echo mode switch results in an audible delay although not particularly prominent delay on positions 1,2 and 4. There is a strong hum and little signal on positions 3,5 and 6. According to the cheat sheet on the lid “Echo rate decreases in the order of 1-2-3. Positions 4-5-6 give you soft echo with complex effect”. From the circuit diagram modes 1,2 and 3 select either playback head 1,2 or 3 through JFET switches. Using a simple diode matrix, modes 4,5 and 6 select either 1+2, 2+3 or 1+2+3. So any mode that involves switching Playback 3 is compromised. Either playback channel 3 (head and or pre-amp) is compromised or the switching voltage or JFET is dead.
Echo Intensity easily goes into echo feedback (VR18 sets the intensity limit).
The spring reverb hums because of the proximity of the step down transformer.
The output tone controls and the output level switch seem to work and the A+B and B jacks output signal as expected.
Sound on sound produces a strong signal (SonS level is VR14).
Either this unit has a power rail problem, or all the presets have drifted a long way, or someone has been inside and fiddled with all the presets without knowing what each one does.
Parts ordered – I ordered two Service Kits for the RE-101,201,301,150 at 110 AUD each (£67.41) on the 18/08/17 (around then anyway)
Paid a customs charge on 07/09/17 of £ 32.69
Ordered a TA7200P from Ebay 8.40 Euro paid by PayPal 07/09/17.
5 x Stainless steel thumb wheel nuts £ 3.99
1 x high intensity LED to replace the incandescent pilot light £ 00.50
2 x service kits – from Visa 21/08/17 £123.62 + £3.70 fee = £127.32
Customs charge £32.69 – from Visa 08/08/17 £32.69
Postage for the second set of kits – from PayPal 28/09/17 AU $ 23.70 £14.47
Space Echoes – Invoiced to date – 2007240 18/03/17 RE-150 Space Echo £68
Invoice for this RE-301 – 2007275
Repair LoG Les Paul Gold top copy SN: xxxxxxxxx ‘Made in U.S.A’ actually made in China
14/08/17 Copyright reserved Terry Relph-Knight
Supplied fitted with a set of 0.009, 0.010, 0.016, 0.023, 0.030, 0.040 strings ? With a black hard case branded ‘Gibson USA’.
Value – £90?? Weight – 3.2kg. 7.054lbs.
This guitar is not a re-branded knock off, rather it is a fake, as it attempts to look like a genuine Gibson gold top Les Paul. On a cursory glance from a few feet away it is surprisingly convincing. The owner did not tell me how much he paid for it, but it was obviously not a lot of money. As delivered this guitar had not been carefully assembled or set up. The interesting thing is that, once the various problems had been fixed and the set up adjusted, it became a really fun guitar to play. It felt and sounded good and had a charm all its own. Initially this was a rush job as the owner wanted the basic problem with the output jack fixed before leaving the country for a few weeks.
Body – Made of mystery wood, certainly not mahogany, hard to tell how many pieces (one join line is visible at the edge of the body). The exposed wood surfaces inside the guitar are quite pale – it could be poplar or pawlonia. Overall the guitar is very light weight for a ‘Les Paul’. Gold top with cream binding on the top edge. Back and sides in a very dark red translucent finish. The back of the guitar appears to have a mahogany like veneer across it to disguise any joins in the body pieces
The carved top is almost certainly two or more separate pieces Carving / sanding is a little crude in places – there is a gap under the top edge of the bridge pickup.
Neck – Also mystery wood. Cream binding on a quite black fretboard, again of mystery wood, but has the appearance of something between ebony and rosewood (possibly black dyed). 22 flatish jumbo frets. Quite sharp fret ends. Moto flared parallelogram fret markers.
The serial number and the Made in U.S.A have been laser cut down to the wood through the finish. A technique that Gibson has never used. The headstock is not quite the right shape, it is too narrow. It does have the ‘Gibson’ logo inlaid on the headstock in abalone shell and Les Paul model in the gold script (actually does not look quite gold, it is more of a dull yellow). Very crudely cut and too small truss rod ‘bell’ cover with Les Paul STANDARD roughly hot stamped in silver. Moulded plastic nut, obviously not Corian.
Hardware – Crude copies of the Gibson Deluxe / Kluson tuners with rather grey ‘green’ plastic tulip head buttons. Spacing and fitting of these tuners is quite sloppy. Two open top black bobbin humbucker pickups with flush steel poles in each pickup (no adjustment screw poles) and probably ceramic magnets. Chrome plated copy of a Nashville Tune-O-Matic bridge with chromed zinc saddles. Bridge posts are 6mm with slotted screw heads. Chrome plated stop bar – screwed down as far as it will go to the body. Gold bell knobs. Rather yellow moulded plastic elevated pick guard.
No internal screening paint or screened cables. Very crude disc around the pickup switch with RHYTHM and TREBLE seemingly dyed in to the surface. Strap buttons have a very shallow flare.
Problems – A wire to the output jack has snapped. The jack socket itself was loose and had probably rotated, snapping the very flimsy connection wire.
The low E and the G tuners are loose on their attachment screws. The tuner post push in ferrule for the G string is loose in its hole.
Generally sharp fret ends.
With the strings removed was possible to see that the rear side of the plastic nut was quite rough where the strings slot had been hacked into it.
Last minute problems with high and low frets above the 12 fret.
Work done – Unsoldered the jack socket completely and cleaned up the solder tags. Fitted a toothed lock washer to the jack socket, tightened the retaining nut onto the jack plate and then dabbed on some clear nail varnish to the nut and threads on the outside to inhibit future loosening. Cut back re-stripped and tinned the connecting wire and re-soldered the connections to the jack socket. Screwed the jack and its plate back onto the body.
Plugged in the guitar to check for proper function and playability.
Second phase of work done – Hammered down the high threaded bridge insert, so it is at least flush with the top of the guitar. Removed the two loose tuners, plugged the over large screw holes with toothpicks and superglue. Glued in the loose G ferrule with a dab of super glue and refitted the tuners. Cleaned and polished the fret board and frets, including smoothing down the fret ends.
Rubbed down the rough spots on the nut and cleaned up the string slots with nut files and then ‘flossed’ them with the old strings coated in metal polish to polish the string slots.
Converted the existing stop bar bolts into a ‘poor man’s’ locking system by cutting off the bolt collars with a mini-hacksaw and supporting the stop bar on a stack of steel washers (instead of a neater looking Faber spacer).
Re-strung with the D’Addario NYXL 10 to 46s. Set up the action and set the intonation.
Fret problems – hammered down and smoothed various high frets above the 12th. At first G 15 was high then D has 15 low and 16 high. String buzz on the D string only at the 15th fret.
Third phase – 29/11/17 Filed and polished frets 16 and 17 so all the frets in that area read level. Changed the D string, which I had damaged in my haste to hammer down fret 15, and was still buzzing even with the frets levelled.
Diagnostics – All the electronics in this guitar are of low quality and the wiring is rather elementary. The control potentiometers are the small 16mm diameter case types and the pickup switch is the low quality ‘box’ type rather than a leaf spring switch.
The bridge is set up at an angle with the bass side higher than the treble (9mm bass and 6.5mm treble – from underside of the bridge end to the top surface of the body). The treble side thread insert has not been pressed all the way into the body, it sits about 1mm proud of the surface.
Tuners have quite a lot of backlash in the gears (the tuner on the D string in particular).
On closer examination while re-stringing the low E and the G tuners are loose on their attachment screws (the two small screws that fit through the tuner ears on the back of the headstock). This is because at least one of each pair of screws isn’t threaded into wood – they are just spinning in an over large hole and the press in ferrule on the G string tuner is loose and will just fall out. Loose tuners do not help with tuning stability. Tuner spacing is quite irregular, particularly for the high E tuner which is spaced away from the other tuners.
The stop bar bolts are rather short – only 18mm to the lower collar.
Intonation as delivered
In this test (with the old strings) each string is tuned exactly to pitch and then the pitch at the fretted twelfth fret is measured. The results are the error from the perfect octave, in cents.
In this test, each string is tuned exactly to pitch and then the length of string between the tuner and the nut is depressed until it touches the headstock and then released. The figures are the change in pitch in cents following this test.
Intonation adjusted for zero error and tuning stability much improved after the nut slots were polished.
Repair Log: 30th of July 2010 SN:NCxx Fender Custom Shop Limited Edition ‘51 Nocaster made by Fender in Corona USA
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Copyright reserved Terry Relph-Knight 01/10/17
Current value – Can be found on offer for £1,700. Purchased from Wunjo’s for £2,000.
Delivered with a rectangular cream and maroon Fender Custom Shop hard case, including a custom shop certificate and other documentation.
Strung 10 to 52 Ernie Ball STHB
Description – A Fender black guard Custom Shop replica of a 1951 ‘Nocaster’ Telecaster, reliced with all slot screws.
Body – Light swamp ash body in the traditional blond finish. Relic wear under the forearm and around the back edge. The black 5 hole pick guard does indeed appear to be made of a thin (0.0625 inch 1/16) sheet of un-bevelled phenolic material and the top surface is lacquered to make it look blacker and shinier. A small area below the top E string has been rubbed away to simulate playing wear.
Neck – One piece, fat soft V, maple neck with a walnut skunk stripe. Wear through on the lacquer up to the eight fret. 21 thin vintage frets. Headstock carries only the script Fender logo in silver with black outline, Fender Custom Shop V logo on the reverse.
Repair Log Fender Custom Shop 51 Nocaster
Hardware – Kluson style tuners. A single round string tree next to the G tuner. Custom Alnico 3 Tele pickups (bridge pickup has flat magnets). Nickel plated folded thin sheet steel bridge with three brass barrel saddles, 4-40 height screws?. Through body stringing with flat ferrules. Four bolt, chrome plated steel neck plate stamped with the NC77 serial LIMITED EDITION and the Fender Custom Shop V logo. Standard Tele control plate with a three way switch and solid nickel plated brass flat top (slight edge radius) knurled knobs. All cloth wired. Tone and volume controls are modern CTS pots. Unfortunately these pots have no stress relief clip, the pot shaft slides in the collar and is only held in place by the locating post into the middle of the steel clip on cover.
This guitar as shipped from the Custom Shop was originally wired to the ‘51 Nocaster schematic with a 15K (wired between neck and middle on one half of the switch and an 0.05uF cap (wired from the other half of the switch – neck terminal – to ground). These components have been removed and the guitar re-wired to modern Tele wiring by a previous owner.
The original ‘51s had no variable tone control. The wiring offered –
Neck pickup with a set bassy sound (no variable tone control)
Neck pickup with no tone control at all
Both pickups with the second rotary control acting as a blend for the bridge.
The neck pickup has the North of the magnet poles up and the bridge has the South up. The pickups do seem to be arranged for hum cancellation in the middle position.
Centre saddle low E to middle 12 fret 327mm, 325mm high E. 257mm front edge of bridge to middle 12fret. Bridge plate is 3 3/8” long.
Problems – Brought in for noise (hum) and a loose output jack. Guitar occasionally produces loud crackles and hums. Seems related to the tone control.
Work done –
Tightened up the nuts on all the controls, on the switch and on the output jack. Dabbed on some clear nail varnish to help lock the output jack nut in place. Replaced one of the rusted ‘reliced’ pickup screws with a clean screw. Re-bent the cover tabs on the tone controls loose cover, shifted the output jack ground over to the back of the volume control where all the other circuit grounds are. Sleeved the long bare wire on the tone cap. Placed an M3 nut inside the Tone knob as a spacer to stop it scraping on the control plate. Replaced the missing switch tip with a barrel tip (the original barrel tip was included in the case, but the slot for the switch arm was so gouged out that it would no longer fit securely).
Having removed the strings in order to lift the bridge I removed the saddles, sanded them down to remove old string notches and soaked all the screws and springs in WD40 to remove dirt and rust. Also cleaned the bridge plate. With the saddles re-assembled and replaced on the bridge plate I set up the action and intonation.
Diagnostics – Loose output jack. Missing switch tip. Pot nuts are loose. Control plate screws loose.
A quick fret rocker test shows fret 8 is high in the middle and one or two other frets further down the neck are a touch high. Fret surfaces look as though they have been levelled fairly recently, but not re-crowned.
A continuity test showed that the bridge plate and strings weren’t connected to ground. Removing the strings and lifting the bridge plate revealed that the ground jumper between the pickup ground lead tag and its elevator plate was intact. It turns out that all three reliced bridge pickup screws were so rusty they no longer made an electrical connection between the pickup elevator plate and the bridge.
Input jack tip contact seems slack, jacks don’t make a positive insertion. Ground lead from tone cap (cap added by previous owner when the guitar was re-wired to modern wiring) is not sleeved and runs over the top of the volume wiper where it could short out.
The tone control seems loose and repeatedly rotating it fully anti-clockwise often produces loud crackles and hums. Looking closely the steel back cover is loose on its four folding tabs. Ridiculously, the only ground return for the output jack is through a black cloth covered wire that is soldered to the back of this cover. With the tabs to the cover being loose the output jack ground has only a very sketchy and intermittent connection to the guitars circuit ground. Perhaps the 1950’s pots had more reliable connection to ground from the cover, the pots in this guitar are of course modern CTS pots. CTS do seem to have changed to using a thinner, softer steel for the pot casing and the fixing tabs are quite easily loosened through down pressure on the pot shaft.
Along with the bad ground connection to the bridge plate the grounding scheme seems very poor. Fender may have been intending to exactly copy a ‘51 Nocaster, (the Fender shop wiring drawings do show this as how the ground was wired) but in the process they seem to have done some really daft things.
Screws – American guitars have either 4-40 or 6-32 saddle height adjustment screws. The first number indicates diameter and larger numbers greater diameter. The second number indicates thread count – 40 is more per inch than 32.
4-40 is 0.112 inch clearance
6-32 is 0.138 inch clearance
4-40 are smaller screws found in Strat saddles.
So 6-32 is the larger size found in the early Tele 3 saddle bridges.
My DeTemple titanium 3 saddle Tele set has ½ inch long screws in the centre and 3/8 long on the two outside saddles. My Rutters is 3/8 and 5/16.
Bridges like the Wilkinson are metric and use M3 screws. They seem to be all 10mm long.
Black barrel switch tip.
Further work – 20/12/17
The original slot head saddle grub screws stick up and are sharp and uncomfortable under the palm of the right hand. I replaced the original screws (six 7/16” long 6-32 slot head) with two stainless steel 1/4” long 6-32 hex head screws for the high and low E strings and four stainless steel 3/8” long 6-32 hex head screws for the other four strings (1/16” hex key for adjustment).