HammondWiki - Diff: ToneWheelGeneratorOutputLevels

Differences between version 3 and previous revision of ToneWheelGeneratorOutputLevels.

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Newer page: version 3 Last edited on September 4, 2007 6:54 am. by
Older page: version 2 Last edited on September 2, 2007 4:47 am. by
@@ -233,9 +233,9 @@
 90 13.4 4.74 
 91 13.3 4.70 
 </pre> 
  
-The two columns shown here below titled as '' Later BC '' are purely own assumption of what the TG output levels might have been for the later Model A, the later BC, the Model D and the later Concert Model E organs built after the manual tapering scheme was introduced in 1937 but before the sine wave bass TG notes 1 to 9 were discontinued during the era of the 82 note TG's. 
+The two columns shown here below titled as '' Later BC '' are purely own assumption of what the TG output levels might possibly have been for the post 1937 Model A, BC, C , D and the Concert Model E organs built after the manual tapering scheme was introduced in 1937 but before the sine wave bass TG notes 1 to 9 were discontinued during the era of the 82 note TG's. The folowing TG output levels assume that the TG output curve was changed to accomodate the manual tapering scheme but thus far ( Sep 2007 ) I have not yet seen the measured TG output curves of a post 1937 Model A , BC ,C, D , and E organ with the 91 note TG and with the sine wave bass TG notes 1 to 12 so therefore I do not know how accurate the following TG output curve id . 
  
 The following measurements would be taken directly from the TG terminal strip. 
  
 <pre> 
@@ -566,9 +566,9 @@
 The following are the measured TG output levels of the complex tone wheel bass TG notes 1 to 13 of my 1963 L-102 organ. These following TG output levels are at a more or less similar level as that of my late era L-143 organ as well as a mid 60's L-111 organ and a 1971 Porta B organ that I have measured. 
  
 Although the output levels of the complex waveform pedal bass TG notes 1 to 13 might seem to be extremely high , in reality the actual audible volume levels of these bass pedal TG notes 1 to 13 when heard through the bass pedals are at similar volume levels as the rest of the sine wave TG notes heard when playing the organ keyboards . The bass TG notes 1 to 13 first pass through an inductor coil filter that rolls off the buzzy or 'farty' sounding higher harmonics that are a part of the complex waveforms and after this the bass TG notes go to the bass pedal drawbar and then in to the organ pre amplifier. The inductor coil filter causes the complex waveforms to sound much mellower and closer to a that of sine wave bass note and this inductor coil filter also reduces the overall volume level of the bass TG notes 1 to 13 so that they are better matched with the rest of the sine wave TG notes. 
  
-The following measurements would be taken directly from the TG terminal strip.  
+  
  
 <pre> 
 TG 1963 L-102 1963 L-102 
 Note mVpp mV RMS 
@@ -588,21 +588,109 @@
 13 329 70.00 
 </pre> 
  
 The earlier era T-series organs seem to have had a very high treble calibration with the output levels of the TG notes 73 to 91 continuing upwards until the high treble TG notes 85 to 91 reached up to somewhere in the 30 to 35 mVpp region (10.61 to 12.32 mV RMS ). 
- I have heard a 1970 T-300 organ with this high treble calibration and the sound was very thin and nasal sounding and I recalibrated the TG to have a similar output curve as that of the post 1956 console organs and doing this significantly improved the sound of the 1970 T-300 organ. 
+ I did some modification and repair work on a friend's 1970 T-300 organ with the high treble calibration and the sound was very thin and nasal sounding and I recalibrated the TG to have a similar output curve as that of the B3 , C3 , A100 etc organs and doing this significantly improved the sound of the 1970 T-300 organ. 
  
 It is possible that enough people might have complained about this nasal sound with the result that Hammond seem to have gone back to the more normal standard post 1956 type TG calibration for the later era T-series and the XTP organs. The T series and the XTP TG's only had the TG notes 18 to 91. 
+  
+As an example of very thin and nasal sounding high treble calibration of the earlier era T-series organs , the following measurements were taken directly from the TG terminal strip of my friend's 1970 T-300 before I recalibrated the TG to have a much better sounding B3/C3 etc type TG output curve. Note that the TG of the  
+T-series and the XTP series spinet organs do not have the tone wheels 1 to 17.  
+  
+<pre>  
+TG 1970 T-300 1970 T-300  
+Note mVpp mV RMS  
+18 13 4.60  
+19 12.2 4.31  
+20 12 4.24  
+21 11.5 4.07  
+22 11.4 4.03  
+23 11 3.89  
+24 11.1 3.93  
+  
+25 11 3.89  
+26 10.1 3.57  
+27 10.4 3.68  
+28 10 3.54  
+29 9.9 3.50  
+30 9.7 3.43  
+31 9.8 3.47  
+32 10.1 3.57  
+33 9.9 3.50  
+34 10 3.54  
+35 10.3 3.64  
+36 9.8 3.47  
+  
+37 10 3.54  
+38 9.9 3.50  
+39 13.2 4.67  
+40 10.2 3.61  
+41 11 3.89  
+42 13.9 4.92  
+43 11.3 4.00  
+44 11 3.89  
+45 11.2 3.96  
+46 11.1 3.93  
+47 11.9 4.21  
+48 12.9 4.56  
+  
+49 13.1 4.63  
+50 12.2 4.31  
+51 13 4.60  
+52 13 4.60  
+53 12.4 4.38  
+54 12.6 4.46  
+55 14 4.95  
+56 15 5.30  
+57 14.8 5.23  
+58 16.1 5.69  
+59 15.4 5.45  
+60 16.7 5.91  
+  
+61 19.9 7.04  
+62 17.4 6.15  
+63 12.3 4.35  
+64 20.9 7.39  
+65 19.9 7.04  
+66 49 17.33  
+67 21.5 7.60  
+68 22 7.78  
+69 29.8 10.54  
+70 21.5 7.60  
+71 22.3 7.89  
+  
+72 21.5 7.60  
+73 60 21.22  
+74 24.9 8.80  
+75 24.2 8.56  
+76 27.4 9.69  
+77 20.8 7.36  
+78 30.3 10.71  
+79 23 8.13  
+80 27.1 9.58  
+81 26.7 9.44  
+82 20.9 7.39  
+83 29.9 10.57  
+84 18.5 6.54  
+  
+85 34.3 12.13  
+86 43.5 15.38  
+87 25.4 8.98  
+88 31.2 11.03  
+89 32.1 11.35  
+90 28 9.90  
+91 30.1 10.64  
+</pre>  
  
 I have measured the TG output levels of an early 1970's R-124 organ and this organ had the sine wave bass TG notes 1 to 12 and the levels of these bass TG notes 1 to 12 were at similar levels as that of the sine wave bass TG notes 1 to 12 of the later BC organs. The TG notes 13 to 91 of this R-124 followed the similar pattern as that of the post 1956 console organs. 
  
-Here below are the output levels of the old output level graph called '‘Approximate output voltage readings of organ  
- Generator frequencies 1 to 91’’. 
+============================================  
+  
+ Here below are the output levels of the old Hammond output level graph called '‘Approximate output voltage readings of organ Generator frequencies 1 to 91’’. 
 The ‘’Old Graph # 1 ‘’ is of the stronger output curve for the Model B organs with serial numbers between 4000 and 5075. These organs had the untapered manuals. I assume that this output curve also applies to the earlier Model A organs. 
 The ‘’Old Graph # 2 is of the weaker output curve for the Model BC organs with serial numbers above 5075 and Model E organs with serial numbers above 8000.These organs had the manual tapering scheme. 
  
 The following measurements would be taken from the GG output terminals of the preamp whilst the appropriate drawbars are pulled out and the appropriate keys are played. 
-  
 <pre> 
 TG Old Graph #1 Old Graph #2 
 Note AC Volts AC Volts 
 1 3.3 0.8 
@@ -703,8 +791,10 @@
 89 0.36 0.22 
 90 0.33 0.21 
 91 0.3 0.2 
 </pre> 
+  
+================================================  
  
 Here below are the output levels shown on the 1940’s Model G service manual and the B3 / C3 service manual . 
 The Model G manual instructs to use a 4 K ohms per volt voltage meter and the B3 / C3 manual instructs to use a 1 K ohms per volt voltage meter. 
  
@@ -812,15 +902,17 @@
 89 0.8 0.2 
 90 0.75 0.5 
 91 0.6 0.25 
 </pre> 
+  
+=========================================================  
  
 CUSTOMIZED TG RECALIBRATION OF KON'S RECAPPED 1962 C3. 
  
 For many years I have been very interested in learning about how the TG calibration affects the sound of the Hammond organs and I know that some Hammond technicians do recalibrate the TG's of the organs of their professional customers. The late Bill Beer in particular was known to recalibrate the TG's to produce what he described as a "hot bitchin fat and ballsy sound" and he also recalibrated the TG's in order to complement his proprietary solid state preamps and high power solid state Leslies. 
  
 Out of curiosity I have recalibrated the whole TG of my 1962 C3 a few times in order to find out what kinds of TG output curves produce the best sound and currently I have a non stock customized louder and fatter than stock sounding recalibrated TG output curve. 
-An advantage of the louder than stock TG output curve of my 1962 C3 is thatt there is a noticeably improved signal to noise ratio because the louder tone wheel signals now mask some of the background mechanical rumble and hum that is often audible under some of the TG notes especially when playing on the upper octaves of the keyboards. 
+An advantage of the louder than stock TG output curve of my 1962 C3 is that there is a noticeably improved signal to noise ratio because the louder tone wheel signals now mask some of the background mechanical rumble and hum that is often audible under some of the TG notes especially when playing on the upper octaves of the keyboards. 
  
 Even though the pickups are now closer to the ton wheels , the sine wave quality of the tone wheels still sounds normal like that of a stock organ. However there is a limit as to how close you can bring the pickups to the tone wheels before the sine wave quality starts to sound dirtier and more warbly thus spoiling the organ sound and I think that the current recalibrationof my 1962 C3 is near the limit and if I try to bring the pickups closer to the tone wheels than what they are now, then the tone wheel sine wave quality will start to deteriorate and thus spoil the organ sound . 
  
 As well as the louder overall output levels of all the TG notes 1 to 91, I have recalibrated the TG output curve to be more like that of the pre 1956 TG output curves that had stronger bass and midrange levels thus producing a fatter organ sound. 
@@ -844,9 +936,9 @@
 Here below are the measured TG output levels of the recalibrated TG of my 1962 C3. These output levels are current as of 2 September 2007. 
  
 The refiltered bass TG notes 1 to 12 with the 100 uf grounding shunt capacitors ( instead of the original stock 16 ohms grounding shunt resistance wires ) do sound more like sine waves but the waveforms are not as pure as real sine waves. Because the refiltered bass TG notes 1 to 12 now do sound closer to sinewaves , I have used the mVpp levels divided by 2.828 conversion formula to convert the mVpp levels of the re filtered bass TG notes 1 to 12 into mV RMS but I do not know if the calculated mV RMS levels of the filtered bass TG notes 1 to 12 are truly accurate. 
  
-Although the output levels of the refiltered bass TG notes 1 to 12 seem to be significantly higher than the TG notes 13 onwards , the actual audible levels aof the bass TG notes 1 to 12 are not as noticeably different from the rest of the TG notes when playing the organ because the TG notes 1 to 12 are loaded down by the key circuits and the drawbar matching transformer. 
+Although the output levels of the refiltered bass TG notes 1 to 12 seem to be significantly higher than the TG notes 13 onwards , the actual audible levels of the bass TG notes 1 to 12 are not as noticeably different from the rest of the TG notes when playing the organ because the TG notes 1 to 12 are loaded down by the key circuits and the drawbar matching transformer. 
  
 The measurements are taken from the TG terminal strip and the TG notes 1 to 12 are refiltered with the 100 uf grounding shunt capacitors instead of the original stock 16 ohms grounding shunt resistance wires. 
  
 <pre> 
@@ -882,28 +974,28 @@
 26 24 8.5 
 27 24 8.5 
 28 24 8.5 
 29 24 8.5 
-30 24.2 8.6  
-31 24.1 8.5 
+30 24 8.5  
+31 24 8.5 
 32 24 8.5 
 33 24 8.5 
-34 24.1 8.5 
-35 24.1 8.5 
+34 24 8.5 
+35 24 8.5 
 36 24 8.5 
  
 37 24 8.5 
 38 24 8.5 
-39 24.1 8.5 
+39 24 8.5 
 40 24 8.5 
 41 24 8.5 
-42 24.1 8.5 
+42 24 8.5 
 43 24 8.5 
-44 24.1 8.5 
+44 24 8.5 
 45 24 8.5 
 46 24 8.5 
 47 24 8.5 
-48 24.1 8.5 
+48 24 8.5 
  
 49 25 8.8 
 50 25 8.8 
 51 25 8.8 

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